Category: Analysis

Anything that I have tested empirically, or explain with detailed calculations, or just generally bother to get all the facts straight.

Post #1943: Microplastic, doing a burn test for carpet fiber

Most internet sources assure me that only four fibers are likely to be found in the pile of modern wall-to-wall carpet. A handful of sources add a fifth (acrylic).  Perusal of current offerings at Home Depot adds a sixth (triexta).

  • Wool
  • Nylon
  • Polyester
  • Polyolefin (including polypropylene and polyethylene)
  • Triexta
  • Acrylic

I think I can plausibly narrow it down to three, in my case, by eliminating these:

Triexta appears to be new enough that it’s not going to be the fiber in my 20-year-old wall-to-wall carpet.

Acrylic appears rare enough, in wall-to-wall carpeting, that I can’t actually find any roll-type carpet made with acrylic fiber currently offered for sale.

Polyolefin fibers appear to be used only in the cheapest carpet materials.  At Home Depot, that’s what their self-stick carpet tiles are made of.  That’s not going to be the basis for my well-wearing 20-year-old wall-to-wall.

N.B. 1:  SD means solution dyed, that is, that is, the plastic itself is dyed before the fibers are spun from it.  As opposed to dying the fibers after-the-fact.  This apparently is by far the preferred method for durability in modern carpeting.

N.B. 2:  Olefin (a.k.a. polyolefin) is a polymer (long molecule made from simple building blocks) where the basic building blocks are straight-chain alkanes (carbon and hydrogen and nothing else).  If you make it out of propane feedstock, you get polypropylene.  If you make it out of ethane feedstock, you get polyethylene.  I assume they use polyolefin when they make the fiber out of whatever’s handy, or from a mix of feedstocks.

Burn test

The most commonly-suggested way to tell what a carpet is made of is to burn (a bit of) it.  Condensing the guidance from this site:

Wool barely burns, extinguishes itself, leaves ash, and smells like burning hair.

Nylon burns well, with a smokeless blue flame, leaves a gray/black blob of melted plastic.  And stinks.  (I’ve sealed the ends of enough nylon rope to know that.  It’s your classic burning plastic smell, but does not stink quite so badly as the smell of burning electronics, which is typically the smell of burning PVC (plastic wire insulation).

Polyester burns well, with a smoky orange flame, sputters and drips as it burns, leaves a shiny plastic bead, and smells “sweet” as it burns.  (Really?)

Pretty sure this carpet isn’t wool.  So it boils down to burning a bit of it, and seeing if it stinks.  If so, it’s nylon.  If not, polyester.

What I didn’t realize is that you need a pretty good chunk of fibers to be able to do this test.  First time I tried it, I had a fluffy bit of fibers, and they simply shrank away from the flame.  Second time I got an entire piece of yarn, twisted it tightly, and got it to burn.

Results:  Sputtering flame, no ash, and no stink.  I’m pretty sure my carpet is polyester.  I could refresh my memory with a bit of nylon cord, or burn a bit of known polyester fabric, but I think this all makes sense.  Plus, burning nylon really stinks.  Like “don’t do that inside” stinks.  And while this did not smell “sweet”, this basically didn’t smell like much at all.  Which pretty much rules out nylon.

I may try some different test, if I can find one.

But odds are, given that this is 20-year-old decent-grade grade wall-to-wall carpet, with some worn spots, clearly made of synthetic, and the fiber burns without a stink, this is polyester.

Conclusion

The entire floor of my house is covered with the cut ends of polyester yarn.  And has been for the past 16 years or so.

All this time, not only did this not bother me, heck, it was downright comfy to walk on.

But now that my eyes have been opened, I see this as a comfy source of microplastic polyester fibers.

Should I care about that, or not?  Or do anything differently, now that I know?

Time to let this percolate a bit more.

Post #1942: Microplastic, some more targeted questions.

 

In my last post, I pinned down what I did and didn’t know about microplastic.  And, while I don’t (yet) think this spells the end of civilization, what I learned has given me pause.

With the just-prior post as background, I spend this post homing in on the questions that I should be asking.

They are:

1)  What are my likely sources of greatest exposure?

2)  How does this stuff break down?  What is the half-life of microplastic, particularly fibers, in various environments (including human tissue).

2B)  Are we seeing this topic frequently in the popular press because microplastic has been building up in the environment (that is, it’s now a much greater hazard than in the immediate past), or because we’re looking for it and/or we now have the means to find it?

3)  Are nano-scale (really tiny) fibers a particular concern?

I’m only going to address the first question, in this post.

Understand my background as a health economist.  Surgeons have been implanting chunks of plastic and metal into people for more than 70 years.  (The first pacemaker implant took place in the late 1950s.  Modern metal-and-plastic hip replacements go back somewhat further.)  So the right materials, properly chosen, won’t interact with the body at all.  OTOH, there’s a long list of materials that were tried and rejected, because they were not so inert.

So my prejudice is that incorporating random bits of plastic into your body is probably a bad idea.  The only question is, how bad is it?  And can you avoid it?

Wall-to-wall paranoia

The first question to ask for any environmental health hazard is, 1)  What are my likely sources of greatest exposure?

For airborne fibers, if I walk through it logically, my greatest source of exposure almost certainly has to be the wall-to-wall carpeting in my home.  It’s indoors, it contains a huge amount of fiber, it’s clearly synthetic fiber, and it is constantly being abraded by walking on it.  And it’s “clipped”, that is, every strand of carpet yarn has been sheared off, so that it’s an entire floor surface consisting of the cut ends of synthetic yarn.  In my house, every floor surface save bathroom, kitchen, and foyer is covered in the stuff.

For me, it’s a big, fiber-generating surface that I shuffle my feet across, every time I change locations within my house.

Reading up on it, I’m guessing it has maybe 60 ounces of carpet pile per square yard, a.k.a., “face weight” 60 carpeting.  Doing the math, that means my house contains somewhere around 700 pounds of carpet fibers.  In the form of short pieces of yarn, with their cut ends exposed, for me to walk on.  I’m pretty sure that outweighs all other cloth in this household, by a wide margin.  True, on any given day, most of it just sits there.  But so does most of the clothing in my closet.

I can only think of two things arguing against this being my greatest source of airborne synthetic fiber exposure.

The first is that, whatever it’s made of (I have no clue), it’s made to resist abrasion.  It was here when we moved into this house in 2007, and it looks about the same now as it did then.  (To within my ability to tell.  What I mean is, no obvious new wear spots have developed in the past 15 years.)

The second is a potential “inverse-square-law” for inhaled fiber concentrations.  That is, for a given rate of fiber shedding, the closer you are to the source of the airborne fibers, the more of them you may be likely to inhale.  If that’s true, then the fibers shed from stuff that’s right under your nose — shirts, sweaters, scarves, coats — might matter more than the fibers shed at your feet.

And if I put all that together, I come up with the obvious conclusion that crawling around on wall-to-wall carpet may not be smart.  Not that I’m planning to do that any time soon, if I have any say in it.  But the point being that having infants crawl around on your wall-to-wall carpeting might require a rethink.  Putting that differently, if you’re not worried about your kids crawling around on wall-to-wall carpet, I don’t see much point in being worried about this topic at all.  Because, outside of a factory, it’s hard for me to imagine where you could get a higher concentration of inhaled artificial fibers than in crawling across modern wall-to-wall carpeting.

We have met the enemy, and he is us.

In my case, I’m going to start by trying to figure out what my carpet is made of.  It was here when we moved in, and I have no clue what the fiber is.  Nylon is a good guess, and everything I read says that nylon, in particular, is a fiber that you’d like to avoid breathing in, owing to what it produces as it slowly breaks down.

And I may be a little more diligent in vacuuming.  Given that the vacuum (in theory) has a HEPA-level filter on it, that (in theory) couldn’t hurt.

Conclusion:  What to do when you’re flying blind

From the prior post, it was absolutely clear that routinely inhaling a lot of nylon fiber is bad for you.  There’s even a name for the resulting condition — flock worker’s lung.

But so what?  Inhaling high levels of almost any fiber or powder is bad for you, be it coal dust, silicon dust, cotton dust, copier toner, wood dust, or what have you.

It’s still an open question as to whether or not there are identifiable health effects from absorption of microplastic at levels commonly found in the environment.

But, from my own perspective, given how picky medical device manufacturers are about the materials they will use for implantable medical devices, it’s a pretty good bet that inhaling and ingesting random plastic bits and fibers is probably not good for you.  How bad, exactly, we can argue about.  But almost surely not a good thing.

My first thought, in a situation like this, is to test for it.  Measure it.  See what my exposure is.

But I don’t think that’s possible, practically speaking.  I already have a “PM 2.5” meter, bought in response to the Canadian forest fires of 2023.  That almost uniformly shows lower airborne particulate levels inside my house than outside.  And that responds to all kinds of particulates, of which the tiny minority is likely to be microplastic fibers.

So this is a case of flying blind.  I can’t tell how much I’m exposed to and I have no clear idea what harm that exposure might do, anyway.

In that case, I can at least try to identify the easily-avoidable sources of microplastic, and so reduce my exposure until better information develops.  I might even go so far as to change what I buy, to avoid funding the production of even more items that shed microplastic.  (E.g., avoid synthetics in my next batch of shirts).  But I’d want to look at the full implications of that first.

So I’m stuck at the “identify my exposures” stage.  My water filter appears to take care of most of the microplastic that might make it into my tap water.  (Though I have no idea what it does with the very smallest particles).  And for airborne fiber, my biggest exposure has to be wall-to-wall carpet.  But this house was built for it, and replacing the existing wall-to-wall with hard-surface flooring would be ludicrously expensive.

Time to step back and let this percolate a bit.

Post #1936: What if this is as good as it gets?

 

Source:  Data are from U.S. DOE, Sources: U.S. Energy Information Administration, Form EIA-860, Annual Electric Generator Report. U.S. Energy Information Administration, Form EIA-861, Annual Electric Power Industry Report. U.S. Energy Information Administration, Form EIA-923, Power Plant Operations Report and predecessor forms.

When technology produces big leaps in energy efficiency, it’s pretty easy to make meaningful reductions in your carbon footprint.  Just buy newer stuff.

But as a long-term observer of this issue, it seems to me that technology-driven gains in energy efficiency are hitting their limits.  There are a lot of important areas — cars, fridges, lighting, and even electrical generation itself — where any further reductions in carbon footprint look a lot more difficult.

What I’m trying to say is, looks like technology has already grabbed the low-hanging fruit.

I’m not going to belabor the societal implications of this.  For me, this means that once I’m driving an EV and living in a house with an efficient heat pump and LED lights, there are no more easy reductions in my household carbon emissions.  Nor are there likely to be, for the foreseeable future.  Lifestyle changes, yes.  Effortless reductions in emissions, no.

Maybe this is as good as it gets.

Continue reading Post #1936: What if this is as good as it gets?

Post #1933: A short, simple explanation of U.S. immigration law

 

/s.  The title is sarcasm.  This post isn’t about explaining U.S. immigration policy.  It’s about giving up trying to understand it, let alone explain it.

U.S. immigration policy is a stew cooked from ancient and modern quotas, agribusiness needs, humanitarian concerns, special exceptions, vestigial ethnic, racial, and religious bias, aftermath-of-war, left-over anti-communism, workforce shortages, national security issues …you name it.

It’s a dish where everybody gets to toss in an ingredient.  Or maybe everybody who can pay to play gets to.  It’s hard to tell.

Policy consists of turning a blind eye to the results, until it’s politically expedient to do otherwise.

 

And by “blind eye”, I don’t mean merely pretending that those folks don’t exist.  Although there’s plenty of that.

It’s knowing they are there, and dismissing it with a shrug.  Ever wonder why they don’t just impose stiff fines on the businesses who hire illegal aliens?  I mean, putting all the right-wing nonsense aside, if nobody would hire you, there wouldn’t be much incentive to immigrate here illegally, would there?

Ponder this:  About 44% of paid U.S. crop workers are illegal aliens.

Who says so, and how do they know?  Who says that so many agribusinesses engage in such a gross violation of Federal law?  The Federal government does.  That’s straight out of the U.S. Department of Labor, National Agricultural Workers Survey.  (From their 2019-2020 survey results summary, available as a .pdf at this link.)  And that’s the percent of folks who were willing to be interviewed, and willing to admit that they lacked legal status to work in the U.S.   But that’s after excluding all workers under H-2A temporary agricultural worker visas, from the sampling frame, to begin with.)

So it’s not as if this is some unknown, unquantifiable practice.  It’s an integral part of the U.S. food supply.  It continues because in normal times, nobody is quite crazy enough to try to disrupt that without having something else ready to take its place.

Which, needless to say, we ain’t got.

For the past few decades, the “politically expedient to do otherwise” periods seem to occur just after peaks in immigration.

And since we’re having a peak now, you’d expect another round of doing something about it. Beyond the billion or two we’ve been spending each year,  now, to fix the worst holes in the Mexican border.

And so, I finally arrive at the cause of this particular screed.

By report, a large majority of U.S. Senators are on board with beefing up security at the Mexican border.  Among other things.

But it sure looks like nothing will happen, because the Republican candidate for President sees it as too good a political issue to allow it to be solved on somebody else’s watch (reference).  And as an added bonus, we can make Putin happy by hanging Ukraine out to dry.  As part of our non-action on this issue.  And the Governor of Texas can defy the U.S. Supreme Court, with impunity.  Ah, that’s an overstatement, but it’s close enough.  Narrowlly construed, I think the Court ruling merely means that the Border Patrol can continue to remove the razor wire that gets in the way of them doing their jobs,  even as the Texas National Guard continues to lay more razor wire.  Not because it makes sense, or is effective.  But because that’s unbeatable political theater.

This is U.S. immigration policy?  Yep, it’s what passes for it, in the current situation.

Define U.S. immigration policy?  Apparently, it’s whatever the Republican executives want it to be.  Nothing more and nothing less.

Maybe I see the past through rose-colored glasses.  Maybe it’s because I spent a decade working for a U.S. legislative-branch agency, and ended up with a lot of respect for then- members of Congress.  But I swear that the U.S. Congress didn’t used to be anywhere near this screwed up.

Post #1930: Luminiser lantern, much cheaper to run than a flashlight using disposable batteries.

Above, the Luminiser lantern being powered by a candle (left), and that candle alone, right.

In my just-prior post, I worked out the basic efficiency numbers for the Luminiser candle-powered electric lantern.  It’s vastly more efficient than, say, a mantle-based oil lamp, such as an Aladdin (r) lamp.

I was so struck by how well the thing worked …

Scratch that.  I was so struck that the thing worked, at all, that I neglected to show any numbers on  operating costs.  Let me fix that now.

If you are “on the grid”, nothing is as cheap as plugging an LED lamp into the wall.  No surprise there.  Not by a longshot.

But suppose that, as a moral issue, you would not allow the general use of electricity in your home.  You live in a home that is not merely “off the grid”, but one that is purposefully and thoughtfully un-electrified. For the sake of argument, let’s say you would selectively allow battery-powered devices, when useful and necessary.  A flashlight, for example, might be OK, but a battery-powered television would not.  But you had to use disposable (alkaline) batteries, for such devices, because there’s no place to charge your rechargeable batteries.

That’s all by way of setting up the comparison.  How would the operating cost of this candle-powered lantern stack up against that of a standard battery-operated lantern or flashlight using cheap, disposable AA alkaline batteries?

Turns out, depending on what you burn in your Luminiser, it’s either vastly cheaper or merely a lot cheaper, than producing the same amount of light with disposable AAs.

I didn’t expect that, and I find it kind of interesting.   Despite the seemingly Rube Goldberg nature of this device — you use the heat of a little oil lamp (“oil candle”) to run a thermo-electric generator, to power some LEDs — the running cost of this is vastly lower than using disposable AAs in a flashlight.

Here are the results of my cost calculation.  Assuming I haven’t slipped a decimal point somewhere, the Luminiser powered with ordinary gas-pump K1 kerosene costs about 3% as much to run as a battery-operated lantern powered with disposable batteries.

Description of the calculation follows.

A few key details

This calculation assumes the following prices, current as of January 2024:

  • 33 cents per AA battery, based on a box of 60 currently at Home Depot.
  • $5/gallon for K1 kerosene (roughly the U.S. national average right now).
  • $15/gallon for Kleen Heet deodorized kerosene (Home Depot price).
  • $30/gallon for paraffin oil (the finest fuel for flat-wick oil lamps), based on the current ACE Hardware price.

For the output of the Luminiser, I’m just accepting the manufacturer’s specs of 200 lumens, for 8 hours, using one 44 milliliter oil candle.

The only hard-to-pin-down unknown is how many lumen-hours you can squeeze out of the typical disposable alkaline AA battery.   This is hard to pin down from manufacturers’ published data for many reasons, not the least of which is that they’ll lie.  But in addition, modern flashlights contain circuits that will turn down the brightness if they are left on.  And, they’ll get dimmer as they run, in any case.  Manufacturers tend to publish data on maximum brightness, and then on run time, where (unstated) the run time is mostly at some much lower brightness.  This means you can’t just multiply published lumen numbers by published run time numbers.  That will typically vastly overstate actual light output.

In my post on candles and lanterns I used an example of a real-life device that produced about 300 lumen-hours per AA battery.  That was a marine distress signal, and likely had been optimized for long battery life.  Similarly, this Nitecore flashlight works out to about 250 lumen-hours per AA battery, on low.

The figure of 300 lumen-hours for a typical AA alkaline battery is consistent with a typical AA alkaline battery capacity of 3 watt-hours of energy, and an overall energy efficiency of LED/driver circuit of 100 lumens per watt.  The AA alkaline capacity figure is pretty much a known, and the lumens-per-watt figure is at the high end of the current crop of off-the-shelf hardware-store lights.  (E.g., 90 lumens per watt for these LED bulbs (Home Depot reference).

Close enough for this kind of calculation.

Addendum:  Re-using/replacing the oil candle.

Edit 1/22/2024:  One day later, and this is obsolete.  See next post for making the permanent refillable replacement for these.

Above:  Original oil candle, 3/16 twist drill, glue syringe, and tiny drill (for air hole).

Below:  Luminiser burning with factory-original candle, and with refilled candle.

The key to operating this cheaply is to use some sort of re-fillable oil lamp to power it.  As shipped, the device comes with a small disposable oil lamp (“oil candle”).  That’s engineered to work correctly with this device, but is an expensive way to produce light.  To run it cheaply, you need to a way to use off-the-shelf kerosene or lamp oil to power this.

I did the obvious thing and demonstrated that I can, in fact, refill the little disposable oil lamp that comes with the light.  At least once.  Drill a hole just big enough for a glue syringe, drill a second smaller hole for to release air, fill the syringe with lamp oil, and inject in into the oil candle.

That works fine.    Light might be a touch dimmer, consistent with using lamp oil (paraffin oil) for the refill, which by reputation will not burn as hot as kerosene.  But if it is dimmer, it’s not dimmer enough to matter.

Lamp oil and kerosene have high flash points, so I’m not terribly worried about the little open holes in the shoulder of the oil candle.  Other than as a spill risk.  Pretty sure the plastic enclosure (and the plastic oil candle itself) would melt before it got hot enough to flash over the raw lamp oil.

But the wick on these disposable “oil candles” does not appear to be adjustable.  Or, at least, not without a lot of effort.  So this looks like it may work once or twice, but not indefinitely.

In the long run, I’m probably going to adapt one of my small (night-light-sized) oil lamps for this purpose.  These lamps are just a few inches tall, and take a round cotton-cord wick instead of a traditional flat oil-lamp wick.  They can produce a flame that’s about the size of the flame produced by this oil candle.  So, by inference, they should be just about exactly hot enough to run this device as the oil candle does.

The Luminiser seems like a robust device, in terms of fuel source.  People have run it successfully using a variety of setups for candles, for example.  Separately, I got it to run by simply sitting it on top of the chimney of one of those miniature oil lamps.  It’s no surprise that refilling the disposable oil candle with lamp oil works well. 

At this point, I’m sure I can find a setup that is both convenient and works well.  But I need to work up something a little more permanent, and a little less hazardous, than any of these makeshift solutions.  I should probably also muck about with the electrical side a bit.  For example, see if I could I gin up a USB charger circuit, and splice it into this.  But that’s for another day.

I’m not usually one to fawn over technology.  But I am reminded of Arthur C Clarke’s dictum:  Any sufficiently advanced technology is indistinguishable from magic.  I mean, I know how it works — as discussed in the last post, it’s a TEG.  But at a gut level, you feed this gizmo a little tiny candle flame, and it spits out enough light to read by.  Not magic, but it sure looks like it.

Post #1929: The caveman wants his fire, or, better to light one candle.

 

I just bought a candle-powered electric light, on Amazon.  The Luminiser, for $20.

What attracted me to this device, aside from the low price, is that it seems like such an irredeemably stupid concept.  Perfect for the headlights on your horse-drawn EV.  Or perhaps to replace the light bulb inside your ice-powered electric fridge.

It’s almost as if some nerds took steampunk literally, glommed up a bunch of money via Kickstarter, and created this pseudo-retro-techno-thing.  Which is, in fact, how this was developed.

But all that aside, a) it works like a charm, b) the underlying tech is pretty interesting and mostly, c) it’s a vastly more efficient light source than the candle that drives it.  And d), I’ve been wanting to own a device of this type for quite some time.

In fact, in terms of in-the-home, fossil-fuel-fired lighting — oil lamps, candles, Coleman lanterns, Aladdin lamps, gas-mantle lamps, and all of that — this is by far the most efficient one you can buy.

So chalk one up for steampunk, as I sit here typing by the light of that lantern, warmed ever-so-slightly by the candle flame in its heart.

In any case, I’m going to use this new toy as my excuse for running the numbers on the entire range of lighting — from candles to LED lights — that I have in my home.

But I’m leaving the deeper moral question for another day.  Would the Amish accept this?  At root, this two-step light generation process is no different from a mantle-type oil lamp, which is a technology generally acceptable to the Amish.

Continue reading Post #1929: The caveman wants his fire, or, better to light one candle.

Post #1928: Will those who succeeded in immigrating illegally please raise your hands, part II

 

In the prior post I established some basic facts.

1:  We’re still running somewhere around 2M unsuccessful attempts at illegal immigration, per year, at the Mexican border.  This is about a third higher than the previous peaks in FY 1986 (1.6M, Reagan) and FY 2000 (1.6M, Clinton).

Source:  Ultimately, the data are from US DHS, but read the prior post to see what I had to do to generate a consistent timeseries, including COVID-based expulsions,.

2: There are no hard numbers on the count of successful attempts at illegal immigration, per year, at the Mexican border.  That’s the subject of this post.  How do they estimate the number of illegal immigrants successfully crossing the Mexican border?

3:  The Congress has been funding increased personnel, barriers, and tracking technology at this border for decades, and continues to do so today.  That includes 1986 legislation that doubled the size of border patrol staff, and 2006 legislation that authorized 700 miles of walls/fences.  In recent years, the Congress has been funding “border barrier construction” at the rate of about $1.5B/year.  I believe this funding is what Biden administration is using to patch a few of the worst known holes in the Mexican border, in Arizona.

Source:  DHS Border Barrier Funding, Updated January 29, 2020, Congressional Research Service
https://crsreports.congress.gov, R45888   NOTE that there’s a large pot of money not under the control of DHHS that is not accounted for in the recent-year data.  As of this writing, I don’t know what that’s being used for.

I recommend that CRS report, cited just above, because you can see how rational the border control strategy was, at least historically.  To nobody’s surprise, they called in experts from the DoD, and they focused the resources on the easiest/busiest illegal entry routes first (CRS report, op cit, page 2).

That $1.5B a year is in addition to the roughly $6B one-time transfer within the Department of Defense budget, attempted by then-President Trump, to various border security projects.  Of which, only about $2.1B in total is available to be spent, the rest being tied up due to the (ahem) unorthodox way in which the funds were allocated, in part, via a declaration of a National Emergency. (This, as of the 2019 CRS report cited below.)

If you want to know what the DoD has been up to, with the monies re-allocated via declaration of National Emergency, there’s a corresponding CRS report on that, as of 2019, but I couldn’t quite make out what has actually taken place under that funding (reference available on this web page).  Near as I can tell, at the time that report was written, seven sections of border fence/wall were were agreed-upon to be built under DoD funding authority. But it’s clear that funding it this way created a lot of legal and other messes, some of which have resulted in the majority of funds not being spendable for border security.

Efforts by DHS to Estimate Southwest Border Security between Ports of Entry

Rather than re-invent the wheel and do my own research, I’m just going to summarize a 2017 report by the US DHS, with the title shown above (reference).  This is, in effect, a report by the Government, on the performance of the Government, so it’s not clear whether there are any explicit or implicit biases in the analysis.   If nothing else, it’s probably about as good a summary of the technical problem as you are likely to find.

This is a report done at the behest of the Congress, given the attention that then-President Trump was focusing on the Mexican border.  As described in the Report:

Congress has directed the Department to provide more detailed reporting on southwest border security. The Consolidated Appropriations Act, 2017 directs the Department to publish “metrics developed to measure the effectiveness of security between the ports of entry, including the methodology and data supporting the resulting measures."

To paraphrase, how good a job are you doing now, at preventing illegal immigration across that border, and how do you estimate that?

So this report is exactly what I’m looking for.

Total interdiction rate, including those who turn back after crossing the border:  Implied successful illegal immigration rate of about 30% per attempt.

 

The report spends a of time talking about deterrence.  That is, the people who don’t even try to cross illegally, because we’ve made it tough for them to do so.  Or who turn back, once they see US DHS personnel.  And similar.

For example, US Border Patrol (USBP) personnel count “turn-backs”, that is, estimates of the number of persons who cross the border into the U.S., but turn back and return to Mexico once they spot USBP personnel there.

The USBP also counts “got aways”, that is, individuals observed to have made it past border security.  Essentially, these are reported either by direct observation, or by noticing signs of passage and inferring the number of people involved.

From such counts, plus apprehensions, US DHS calculates a couple of “interdiction rates”, that is, the fraction of all persons attempting to cross, who get successfully turned back.  One of those rates relies solely on data that U.S. DHS personnel observe, and so excludes most of the successful illegal immigrants.  A second estimate of the interdiction rate includes some estimate of illegal immigrants who managed to evade US DHS.

In round numbers, by the end of the period, the US DHS estimate for the success rate at crossing the Mexican border is 30%.  The other 70% either turned back voluntarily when they spotted USBP, or they were caught.

(Note that you CANNOT multiply 30%, times the roughly 2 million illegal immigrants caught at the border each year, to estimate the number of illegal immigrants at about 600K per year.  That’s because the TIR above also includes a count of “turn backs”, who are persons who were NOT apprehended crossing the border.  Based on the above, the estimated number of illegal immigrants has to be higher than that.)

But that depends critically on the very last factor above — the estimated (successful) illegal entries.

How do they estimate that?

Survey data, including only apprehensions (not turn-backs), implied successful crossing rate 50% to 70% per attempt.

There are several long-running surveys of migrants where they ask how often they’ve tried to cross into the U.S., and how frequently they’ve gotten caught.  I cannot even imagine what the potential sampling bias issues are for such surveys.  All I can say is that this DHS report summarizes the results of three long-running academically-sponsored surveys as shown above:  Roughly a 30% to 50% chance of being apprehended on any on attempt at border crossing.

So those who were willing to be surveyed — on either side of the border — report getting caught a lot less frequently than the US DHS “TIR” methodology would suggest.

near-border Repeat offenders, the partial apprehension rate:  Implied successful illegal crossing rate of perhaps 50%.

A final method used by US DHS is to track people who were caught and released into Mexico. Guess how many are likely to try it again.  Then see how many they catch a second time.

Once caught, they record “biometric” information, which I guess is fingerprints, face scans, and similar.  (So that they know if they catch them again.)

They restrict their analysis solely to individuals who live near the border.

Using a survey-based estimate, they take a guess at the fraction of those folks who are likely to try to enter illegally again.

And then they count the number that they catch a second time.

That yields the Partial Apprehension Rate shown above.  Admittedly, these are folks who by definition have had some practice at crossing.  But also, by definition, weren’t particularly good at it.  So, FWIW, they estimate that about half of that population successfully immigrates illegally across the Mexican border, on their second attempt.  And they take that estimate — roughly 50% — as a reasonable guess for the overall rate of successful illegal immigration.

Conclusion

I could go on.  This report presents its own complex estimate of likely count of illegal immigrants, but I honestly didn’t follow the logic or the resulting numbers.

The only real bottom line is that the Mexican border is quite porous, and that successful illegal immigration occurs routinely.  You could quibble over just how large a fraction, but as a good working estimate, you’d be justified in guessing that about half the people who try it succeed.

Moreover, there’s no strong trend there.  The is maybe a little harder to cross now, compared to (say) 20 years ago.  But only a little.

We’re currently targeting a billion or two a year at building and reconstructing walls and fences along the border, adding other security measures, and so on.  I’m hardly an expert, but I’m not seeing anything on the plate right now that hasn’t been there for the past couple of decades.

In any case, given the history of this, I think the notion that we’re somehow going to seal that border air-tight strikes me as somewhat far-fetched. Or expensive beyond our willingness to pay, take your pick.

My prediction is that the current Congress — if it can be prodded into action — will do what prior Congresses have done.  Address the worst known points for illegal entry.  Place a few more patches on the existing system.  And wait for the problem to go away for another decade or so.

No matter how you slice it, the influx of a million destitute people a year, in those border states, has to be putting a strain on something.

Despite the rhetoric, some Federal money goes to support whatever-it-is that communities in border states have to spend more money on, in response.  And while illegal (undocumented) immigrants (migrants) are not eligible for (e.g.) Medicaid, the Feds do, in fact, give communities money to deal with the basic humanitarian issues of food and shelter.  (E.g., $290M, per this press release).  Allocated like so, to local charities in those states, showing just the first few listed alphabetically:

But if you read the fine print, none of that applies to successful illegal immigrants, those who got across the border without being apprehended.  Or are not claiming asylum.  And so on.  Those grants to local charities only apply to those who have been “processed” in some form, by immigration authorities.

So at present, there’s a large influx of very poor people, who are almost by definition outside of “the system” and are categorically ineligible for any type of direct Federal assistance.  For example, they can’t get food stamps (reference).  They are, effectively, un-people.

The only major exception is for children.  Even if their parents crossed the border illegally, in theory, the U.S. won’t allow them to starve.  I think.  And schools that take Federal funds have to enroll them.  I think.  Including free and reduced price lunches, if they are not too scared to apply for that.

And so, we have this weird situation in those border states.  Everybody with any sense realizes they’re getting a million or so people a year, currently mostly refugees from bad conditions in South and Central America.  Or just looking for a better life.  Who crossed the border illegally.  And it’s a fantasy to expect that to stop any time soon.  If ever.  But the Feds can’t do anything to ease the resulting strain on state and local governments, because that large population falls entirely outside of the law.

Everybody knows they’re there, somewhere.  Everybody can see that more are coming.  But nobody can help state and local governments deal with the bulk of the problem.  Because that million-a-year influx consists of people who have no legal standing.  And so we carry on, with policy-by-fantasy, or policy-by-turning-a-blind-eye.  Or no policy at all.

Addendum:  Gross versus net, or missing the reverse flow.

Source:  Immigrationpolicy.org

Notice anything odd about the graph above?  If there’s this huge ongoing influx of illegal immigrants … why are all the curves flat?  Why isn’t the estimate of illegal alien U.S. residents rising?

What I’ve looked at so far is the gross inflow of illegal immigrants across the border.   The graph above looks at the net number of illegal aliens living here.  Assuming both estimates are reasonably close to correct, there has to be a pretty big outflow of illegal immigrants, back out of the U.S.

So, as a matter of logic, I’m missing a potentially large flow of people in my overall analysis of illegal immigration.  Some fraction of successful illegal immigrants — those who cross the border illegally, and end up settled somewhere away from the border — eventually cross back.  To get at net illegal immigration, I should, in theory, subtract out that flow.

(And there’s also some fraction of that population lost to illegal immigrants who are granted some form of amnesty, and so convert to legal status.  But there hasn’t been a large-scale amnesty program since Reagan, I think.  Maybe there was one under Clinton?  And then there are attempts to convert the ambiguous legal status of individuals who came here illegally as children but are now grown-up Americans — without legal residency status.)

Historically, there seems to have been a reasonably large reciprocal flow of Mexicans returning to Mexico, from the U.S.  In fact, since 2008, more Mexican nationals have left the U.S. than have entered, by some estimates.  (Or this NY Times article, if you prefer a human interest story to mere statistics.).

To that you’d have to add anybody deported from the interior of the U.S., as only those captured near the border are counted in apprehensions.  (And even there, I’m not sure of the status of long-term illegal residents of communities near the border, who end up being deported as illegal aliens).

By all accounts, if you followed the graph above for another couple of years, there would have likely been an uptick.  But not nearly as much as you might guess, purely from the estimated gross flow of illegal aliens across the border.

Thus, the final lesson for today is that the net growth in the illegal immigrant population in the U.S. is far less than the gross influx of illegal immigrants in any year.

It’s a slight mis-statement to put it this way, but our porous border is porous in both directions.

Addendum 2:  Overstays

Prior to (say) 2017 or so, the single largest source of new illegal U.S. residents every year was individuals who overstayed their visas.  They entered the U.S. legally as tourists, students, or workers, with a visa specifying a defined period of residence, or perhaps legal residence when accomplishing some defined task (e.g., a course of graduate study).  And then the U.S. has no record of their departure, prior to the expiration of that visa.

In the FY 2022 Overstay report, by US DHS, 3.67 percent of persons with such visas overstated their visa, resulting in about 850,000 persons who were, for some period of time, illegal residents of the U.S., because they overstayed their visas.

Aside from that one factoid, I gleaned nothing else useful from that overstay report.  It’s not clear to me how much of that is bookkeeping errors, how much is persons who overstayed by a few days, and so on.  How many eventually left.  And so on.

So it’s hard to make much out of that, except to say that prior to the latest increase in likely illegal immigration at the Mexican border, that was consistently the single largest category of annual “illegal immigration”.  Take that for what it’s worth.

Post #1927: Will those who succeeded in immigrating illegally please raise your hands?

 

This is the first of what may end up as a series of posts on the statistics of illegal immigration across the Mexican border.  

Unlike my usual style, I’m just going to present my conclusions here, and put the citation of sources, evidence, and analysis in separate posts.  If I get around to it.  Because, to be fair, the conclusions aren’t what I expected to see.  And this is a topic where I don’t think people’s opinions are much swayed by evidence anyway.

One simple question:  How do they know?

Source: How to Lie With Statistics,

I didn’t intend to do a series of posts on this topic.  I just wanted a simple answer to what I thought was a fairly obvious question.  The most basic question you can ask about a statistic, as shown above.

That snowballed.  But here’s where I started.

You’ll see various posts and news reporting (loosely defined) claiming that millions of illegal immigrants are coming into the U.S. every year, via the Mexican border.

These claims immediately pinged my bullshit detector, for a very simple reason:

How do they know?

For every law enforcement statistic I know of, official numbers count those who were caught.  But here, how do they count the people who weren’t caught, the ones who made it safely (but illegally) into the U.S., via the Mexican border?

Once you start prying away at that question, you soon discover a whole nested set of additional questions. A set of matrioshka cans-of-worms, if you will.

 

But let’s just stop at the first question.

How do they count the people who successfully illegally immigrate across the U.S.-Mexican border? Continue reading Post #1927: Will those who succeeded in immigrating illegally please raise your hands?

Post #1926: A Prius driver takes a pass on Chevy Bolt “one-pedal driving”.

 

Do electric vehicles (EVs) get rear-ended more often than conventional cars do?

They certainly should.

That’s my conclusion after trying out the “one-pedal driving” mode on my new (used) 2020 Chevy Bolt.   And working through the logical consequences of it.

The practical bottom line of this post is that you should think twice before you tailgate an EV in traffic.  Because the chances are good that they can stop a whole lot faster than you can.   And may give you less warning when they do.

Not convinced?  Keep reading the parts in red, below.

Words do not do it justice: An accurate description of one-pedal driving mode.

Source:  Yeah, I know it’s a front-wheel-drive car.  The Gencraft AI doesn’t, though.  Almost all pictures here are courtesy of Gencraft.

Here’s your typical bland one-sentence description of one-pedal driving mode:  “With one-pedal driving, the car has enhanced regenerative braking, and will begin to slow as soon as you ease up on the gas (accelerator).”

Before I bought a Bolt, my reaction to that was, big deal.  Almost all modern cars do that, to a degree.  Anything with an automatic transmission slows when you take your foot off the gas.  All hybrids use regenerative braking, that is, they slow down by generating and storing electricity, reserving the friction brakes (pads pressing on rotors) as a last resort.

Some EVs can now do it more?  Whoop-te-doo.

Now that I own a Bolt, I know that description is missing a key word:  Abruptly.  Or, rapidly. Or, with great force.  Take your pick.

Taking your foot off the gas in “one-pedal” mode is nothing like taking your foot off the gas in a normal or hybrid car.  You don’t coast, at all.  You stop, pronto.  Not quite a wheels-locked panic stop.  But far faster than I normally stop, and far faster than anyone would reasonably expect me to stop in traffic.  In the Bolt, in one-pedal model, take your foot off the accelerator and you pull a few tenths of a G worth of deceleration.  Enough to pull you forward in your seat.  Enough that there’s no way I would engage that mode in snowy or icy roads.  Enough that I’d think hard about it before I turned one-pedal driving on in a driving rain.

Enough, already.  You get the point.  Here’s a more accurate description of one-pedal driving mode:

The act of lifting up on the accelerator, in one-pedal driving mode, is equivalent to pushing the brake pedal.  Hard.  Your (lack of) accelerator pedal is your brake pedal.  It’s not 100% as much force as you can get, if you actually do mash down the brakes.  But it’s an appreciable fraction of it.

You may again think, so what?  So you can, in effect, actuate the brakes, without hitting the brake pedal.  What’s the big deal?

Keep reading.

Brake lights?  We don’t need no stinkin’ brake lights.

But wait, it gets better.

Prior to mid-2023, some EVs would do that — stop fairly abruptly, in one-pedal mode — without turning on the brake lights.  And no, I’m not kidding about that.  (Reference).

The worst of those were fixed via software update, so now, all EVs on U.S. roads will now show brake lights, at some point, during some level of deceleration, in one-pedal driving mode.

As an afterthought.  Does that make you feel better about it?

But even now, an EV manufacturer’s decision on when, exactly, to show brake lights, during rapid braking in one-pedal driving mode, is entirely voluntary, and entirely up to the manufacturer, here in the U.S.A.  And for all of them, those lights turn on after the car has started slowing down.

Oddly enough, if you see this brought up on-line, you’ll see nothing but apologists for it.  Ah, cars have always had ways of slowing down without showing brake lights.  Let off the gas, in an automatic-transmission car.  Downshift in a manual.  Or, if you’re a jerk, hit the parking brake to stop, to fake out the folks behind you.

But those events were either mild in nature (automatic transmission), or rare and mild (nobody in the U.S. drives a manual these days, and nobody in the last 50 years has been dumb enough to wear out their clutch rather than brake pads by routinely slowing the car by downshifting).  Or required outright malice, like using a hand brake to stop.

Now, by contrast, you’re putting out a whole fleet of cars, for Joe and Jane Driver, all of which are designed to be driven without touching the brakes.  Designed to allow for substantial rates of deceleration without using the actual brake pedal.  And for which the decision about whether, or when, to turn on the brake lights at some point during that one-pedal deceleration, is an option for the manufacturer to decide. 

Let me offer a clear contrast to what you are used to, in a traditional gas car.  There, the brake lights are designed to light the instant you rest your foot on the brake pedal.  Brake lights are actuated by a switch that typically sits directly above the metal bar holding the brake pedal.  That switch has a fine adjustment on it.  You literally fine-tune-it so that the tiniest movement of the brake pedal closes the switch.  Even the lightest possible braking pressure will turn on your brake lights.  Properly adjusted, you literally turn on the brake lights before the brake pads make contact with the rotors.

So we now have a mixed fleet of cars on the road.  For 99% of them, the brake lights illuminate as soon as the driver puts on the brakes.  For the remaining 1%, the lights may come on at some point, after the driver has “put on the brakes”, assuming the rate of deceleration exceeds the manufacturer-specified threshold.

Yeah, what could possibly go wrong with that?

Braking distance versus stopping distance.

Definitions:  Both terms apply to panic stops.  Braking distance is how far your car travels, from the moment that you’ve firmly stomped on the brakes, until you reach a complete stop.  Stopping distance, by contrast, is that, plus the distance you travel during your “reaction time”, that is, the time it takes to say “oh shit”, move your foot off the gas, and hit the brakes.

Honking the horn is optional, but highly recommended here in Northern Virginia.

Now for just a bit of math.

1:  It takes about three-quarters of a second to lift your foot off the gas, and put it on the brake, in a panic stop.  That’s in addition to the initial reaction time — the time it takes you to realize you need to stop quickly.  (Estimates vary, that’s my reading of the literature on the subject.)

2:  At 30 miles per hour, in that amount of time, a car moves about two car lengths.  (Calculated as (30 MPH *5280 FT/MI *(0.75/(60*60) HOURS) = ) 33 feet.

3:  EVs in one-pedal driving mode can initiate an abrupt stop without moving their foot to the brake pedal.

My takeaway from all that is that EVs in one-pedal driving mode should be able to panic-stop somewhere around a couple of car lengths shorter than traditional cars.  That’s not due to better brakes, or better drivers.  That occurs because they begin to brake rapidly before they even move their foot to the brake pedal.

Yeah, what could possibly go wrong with that?

Summary

Shorter stopping distance is just dandy if you’re driving an EV in one-pedal mode.  But maybe isn’t such a plus for the person in a standard vehicle, tailgating an EV in one-pedal mode.

If you are in traffic, behind an EV in one-pedal mode, and the EV in front of you makes a panic stop, you need to be aware that, compared to a conventional car or hybrid:

1: That EV is inherently capable of stopping faster.

2: That EV will give you less time to realize it is stopping.

And nothing about that car will give you the faintest hint that those two factors are in play.

You’ve been warned.

Background:  Regenerative braking the Toyota way, or why Bolt one-pedal mode does me more harm than good.

We changed the brake pads on my wife’s 2005 Toyota Prius sometime around 140,000 miles.  Up to that point, the brakes hadn’t needed any attention.

The crazy thing is, that’s not even brag-worthy.  Going 100K miles between brake jobs is normal for any car with regenerative braking.

The Prius has regenerative braking.  To the greatest extent possible, the car slows down by turning itself into an electric generator.  It converts the forward momentum of the car to electricity, which then charges the traction battery.  Cars with regenerative braking routinely go 100,000 miles between brake jobs.  So says the U.S. DOE.

No material efficiency gains — for me.

The reason for the low brake wear in a Prius is that almost all the braking energy is done electrically.  In an ideal gentle stop, the friction brakes only kick in below about 5 MPH.  (If your rotors have surface rust, and your windows are open, you can hear that happen until you knock the rust off the rotors.)

In an idealized stop from 30 MPH to zero, you can easily calculate the fraction of braking “power dissipation” accounted for by electrical generation versus friction brakes.  Kinetic energy goes as the square of the speed, so, in a hypothetical gentle stop from 30 MPH to 0 MPH, where the friction brakes only handle the part below 5 MPH, the fraction of braking energy is:

Friction fraction of braking energy = 5-squared/30-squared = 25/900 = ~3%

Electrical Fraction of braking energy = 1 – friction fraction = 97%.

In other words, with a reasonably gentle stop, in typical suburban traffic, regenerative braking (Toyota-style) converts about 97% of the car’s forward momentum to electricity.  You don’t get to keep all of that, because there are losses in the electric motor/generators, the wires and charging electronics, and in charging the battery.  Maybe you keep 80% of that, or so.

One rationale offered for EV one-pedal driving is that it improves efficiency by recapturing more of the potentially available energy from braking the car.  That’s because you can literally bring the car to a full stop, and so, in theory, capture 100% of the car’s forward momentum and convert it to electricity.  Of which, again, you might be able to keep and use maybe 80%, after all the relevant losses are factored in.

And that’s the main reason that Bolt one-pedal driving does more-or-less nothing for my driving efficiency.  Because, despite what you may read, the Bolt’s regenerative braking does more-or-less the exact same thing as the Prius, during moderate stops.  In normal (not one-pedal) driving, when I take my foot off the gas, the car begins to recapture energy through regeneration.  And when I push gently on the brake, it begins to capture even more energy through regeneration.  Just like a Prius.  (All you have to do is look at the dashboard, as you brake, to see that this is true.)  And in a normal, gentle stop, with rusty rotors, you can hear the Bolt friction brakes engage at about the same speed as the Prius — about 5 MPH.

I guess if you drive like a bat out of hell, regenerative braking can improve your efficiency somewhat.  Plausibly, those who routinely make quick stops can benefit from converting more of the stop to electricity, before the friction brakes kick in.

But my driving habits were formed during the Arab Oil Embargoes/energy crises of the 1970s.  And I’m cheap, to boot.  So I try to avoid rapid stops.

My gut reaction, from reading about this, is that the real fan-boys for one-pedal driving are, in fact, those who want to drive like a bat out of hell.  They like it for the “sporty” feel, and how it lets them zip around all that much faster.  Which, to me, makes the whole “efficiency” argument kind of silly.  If you drive that way, clearly efficiency isn’t your goal.  You’d get more miles per KWH by not trying to drive the Bolt like a sports car.

So, from my perspective, as far as efficiency goes, one-pedal driving provides a marginal improvement in efficiency, for those with habitually inefficient driving styles.  Turning that around, if you’re a laid-back driver by nature, you ain’t going to get much additional efficiency out of one-pedal driving, beyond what you get from regenerative braking in “normal” driving mode.

Extras for experts, 1:  There is one weird final twist on this, in that, in a hybrid, regenerative braking doesn’t much matter.  It might typically add just 2% to the vehicle’s overall efficiency.  That’s from a combination of factors.  First, even with the efficient Atkinson-cycle engine of a Prius, you start off by wasting 60% of the energy in the gasoline.  Second, with relatively small electric motor/generators, and most importantly a relatively small battery, the amount of regenerative braking force — the amount of current you can safely generate and squeeze into the battery, without damaging anything — is highly limited.   So for the U.S. EPA drive cycle, with its extended periods of fast stop-and-go driving, you tend to show only a modest amount of energy recapture, as a fraction of the total energy used by the vehicle.

In an EV, by contrast, regenerative braking is a much higher contributor to overall vehicle efficiency, as the Federal government measures it.  First, unlike a hybrid, all the inefficiency in converting fossil fuels to electricity is “off the books”, so to speak.  That occurs at your local utility, not in your car.  The calculation of overall car efficiency starts with charging it, so as a whole the vehicle appears to have vastly less total wasted energy, than a hybrid does.  Second, with large motors and much larger battery, you can safely put more current into the battery.  Thus, in a hard stop, an EV can likely capture more of the energy than an hybrid can, prior to applying the friction brakes.

Old dog, new trick — look ma, no brakes!

The first thing about Toyota-style regenerative braking is that it’s absolutely seamless.  In the best case, you wouldn’t even guess that the car had this feature.  Only if you listen very closely, and brake very slowly, can you discern the point at which the friction brakes are engaged.

The second thing about Toyota-style regenerative braking is that hybrids with regenerative braking behave exactly the same as any non-hybrid car with automatic transmission.  Take your foot off the gas, and the car begins to slow just a little bit, just like any other automatic-transmission car (then) on the road.  The harder you push on the brake pedal, the more braking force you get.

Regeneration in the Bolt, by contrast, feels nothing like a normal car in this regard.  It is far more aggressive, even in normal (not one-pedal) mode.  Take your foot off the gas in a Bolt, and you slow much faster than you would in a standard car with automatic transmission, or in a typical hybrid.  I have already had to break myself of the long-learned habit of lifting my foot from the gas when I see a red light ahead.  On the roads around here, If I were to do that in a Bolt, I’d come to a dead stop long before I make it to the light.

But I can live with that.  I lift my foot, eyeball the dash, and look for the something close to zero KW going into or out the battery.  It’s hardly a life-changing difference in driving technique.  Not after I had to re-learn driving for the Prius Prime, and its preference for constant-power (instead of constant-force) acceleration (Post #1618:  There ain’t no disputin’ Sir Isaac Newton).

But switching to one-pedal driving has one potentially life-changing difference:  You may lose the instinct to put your foot on the brake.  If you never need to panic stop, you can literally drive the car in one-pedal mode and never touch the brake.   (Some one-pedal fans brag about doing exactly that.)

So do I, as a 65-year-old guy, now want to train myself to drive in one-pedal mode?  This, when the approach to driving is so different from our other car (a Prius).  And this, where driving in this new style means basically to ignore the brake pedal.

Short answer, no.  Sooner or later, in NoVA traffic, I’m going to have to do a panic stop.  And when that happens, that panic stop happens on instinct.  It took me close to 20 years to get used to ABS, and to lose the instinct to release the brakes in response to a skid, and just keep my foot mashed to the floor.  I really, really don’t want to lose the instinct that tells me to hit the brakes in an emergency-stop situation.

So, it’s not that I couldn’t learn this new trick.  It’s that I probably shouldn’t.  Not with driving two different cars.  And not with my recent entry into geezerhood.  Better to leave sleeping dogs lie.

The Prius Gene

This is a true story.  We bought our first Prius in 2005.  The same week that we bought ours, hundreds of miles away, with no communication between us, one of my brothers also bought his first Prius.

We’re now a two-Prius family.  I think my brother and his wife have been a three-Prius family, with one going off to Prius heaven as a result of a freak highway accident.

My brother says the exact same thing about his Prius, as I say about ours:  It pushes all my buttons, in just the right way.  From the super-smooth acceleration with no gear shifts, to the dashboard feedback on mileage, pretty much everything about the car says “relax, chill, enjoy the drive”.

Maybe we both like that because that’s pretty much the way my dad drove.  Maybe we inherited the genes that give us that bent.  In any case, it seems to run in the family.

It takes some work to drive a Bolt as if you were puttering along in a Prius.  But for whatever reason, by golly, that’s how I choose to drive it.

So, no one-pedal mode for me.  It’s insufficiently Prius-like.

Post #1923: Gym use during our normal winter peak of COVID-19 cases.

 

My wife masked up at the gym yesterday.  Not at random — no matter how much fun that might have been — but because several friends of hers have gotten COVID recently.

Gyms are known to be risky places for COVID transmission.  That was clear from epidemiological analysis done during the pandemic.  And that’s unsurprising, given that COVID spreads by airborne transmission, and breathing hard is part of cardio exercise.

This means it’s time to get back in touch with the most recent statistics on COVID cases in Virginia.  So, without putting in a lot of effort, I’m going to get a snapshot of reported COVID cases in Virginia.

Briefly:  This is just the new normal.  We seem to be on track for our regular wintertime peak in COVID-19 cases.  Winter ’23-’24 looks like it’ll be about the same as winter ’22-’23.  Whatever precautions you thought were appropriate at this time last year are probably appropriate now.

Our regular winter COVID 19 peak

The first thing I note is that we’re on track for what has become our normal winter peak in severe COVID-19 cases.  That, based on hospital admissions for COVID, from the CDC, for the past four winters, as marked:

Source:  CDC COVID data tracker.  Annotations are mine.

Separately, Virginia still tracks total lab-reported cases.  These are individuals who were diagnosed by DNA testing done in labs, not by “quick” testing typically done in the home.  Again, we seem to be on track for an early-January peak in total new reported cases.  Same as for the past three years.

 

Source for both of the above, less my annotations:  Virginia Department of Health.

The upshot is that new cases, and new hospitalizations, are roughly where they were this time last year.

Nor has COVID itself gotten any more virulent compared to last year.  The most recent prevalent strain of COVID (JN.1) appears neither more nor less virulent than any of the other recent strains (per CDC). Nothing has come along since Omicron that has motivated the Powers that Be to use up another Greek letter to name a significantly new strain.  So JN.1 is just the worthy descendent of Omicron.

So — same timing as last year, roughly the same incidence as last year, roughly the same virulence as last year. Whatever precautions you were comfortable taking last year at this time, well, you should feel comfortable taking them again, now.  Because this ought to be the peak of new cases, or nearly, if this year is like the past three.

To be clear, new cases are appearing in all age groups.  This, from Virginia, for the past 13 weeks:

Source:  Virginia Department of Health.

But serious cases overwhelmingly occur among the elderly.  Below are the rates of hospitalization, by age group, from mid-December 2023, from the US CDC.

I don’t want to make light of this.  The same CDC data source shows that COVID-19 cases currently occupy about 5% of all staffed hospital inpatient beds in the Virginia.  And COVID-19 deaths account for about 5% of all current deaths in Virginia.

So COVID-19 is still serious and costly business.

But so is most of U.S. health care.  And my only real point is that it’s not hugely different from last year at this time.  The current increase in cases, mid-winter, is just the new normal.

The new normal, and a little calculation.

Let me quickly redo my “risk of exposure” calculation for my trips to the gym, based on an incidence of roughly 20 new cases per 100,000 per day, here in Virginia.  As I have done in the past, to arrive at a guess as to how many people are walking around in an infectious state, I multiply the raw incidence by nine, to account for a) under-reporting of new cases and b) the average number of days that an infected person walks around being infectious to others.  So I’m starting with an estimate that about 180 persons per 100,000 (0.18%) are currently walking around in Virginia, actively infectious with COVID.

With 25 people in the cardio room at the gym, the likelihood that:

  • Any one person is infectious:   0.0018
  • Any one person is NOT infectious: 1 – 0.0018 = 0.9982
  • All 25 people are NOT infectious:  (0.9982)^25 = 0.9559 ~=0.96
  • At least one person IS infectious = 1 – 0.96 = 0.04 = 4%

Being in the same room as an actively infectious person is not the same as getting infected.  That said, that’s a non-negligible risk.

I’d say my wife was entirely justified in masking up at the gym (along with several others).  Based on evidence, not anecdotes.

And I was plausibly justified in not doing that.  Based on ignorance.

But now that I know what the odds are, yeah, if the rates don’t peak soon, I’ll probably resume wearing a ventilated 3M N95 to the gym.  At least for now.

Avoidable risks don’t change just because nobody’s taking them seriously.