Population Growth

(from Musings and Rants 1985-2016, Marcus Everett 2017, CKCPC3 Publishing, p173, written in 2007)

Several years ago a friend was telling me about a book she had read about the Blue Crab. The life cycle of the Blue Crab begins in bays and marshes along the East Coast from the Mid-Atlantic States to the Gulf States. The mature female can only mate during a 'shed', when she discards an old shell and before the new shell hardens. If she is fertilized during this event, under her 'apron' she will grow a large egg mass, which looks like a big orange sponge. She will then make her way to the inlet of the bay where she has been living to release her eggs into the outgoing tide.

The eggs hatch and the baby crabs spend the first half of their life at sea. When they reach about half of their adult size, they return to the bays to mature and mate. The question of interest, then, is what percentage on average of the thousands of eggs released by a female make it back to successfully mate?

Most people would guess that the percentage is small, and they would be right. But it is possible to be more precise. For a stable population, each successfully breeding female must, on average, produce exactly one successfully breeding female. If the average success rate is greater than 1, the population will grow exponentially; if the rate is less than 1 it will decrease exponentially. An average success rate of 2 would result in the population doubling every generation, a success rate of 0.5 would result in it halving every generation.

One might ask about the poor males, but as long as the survival rate of males is sufficient to fertilize a sufficient number of females, the population growth rates depend almost entirely on the success rates of the females.

The above consideration holds for any sexually reproducing species, whether it's crabs, birds, whales or humans. If the average female success rate differs from 1, the population will either grow or decay exponentially. This fact has rather profound implications for modern humanity.

For most of known human history, the long-term female success rate has been greater than 1, but only barely. Estimates of population growth over the 10,000 years before about 1700 put the average success rate, assuming 20 years for a generation, at about 1.01. This rate of success implies that each generation was about 1% larger than the previous, and that the population doubled about every 1500 years. Wars had little effect, since as was pointed out above only a sufficient number of males are required. (This fact is borne out by the baby boom after WWII - losing a half million males didn't even keep the growth rate flat!) Disasters that affect both sexes cause a short-term stutter, but usually this just makes it easier for the next generation or so to make up lost ground.

The problem is that, over the last 200 years, the industrial revolution together with modern medicine and agriculture has greatly increased the survival rate and therefore the potential female success rate. I say potential rate, since some cultures have voluntarily reduced the rate even below 1. China, in fact, has recently implemented a one child per couple rule which, together with a cultural bias against female offspring, has apparently resulted in an effective female success rate of something like 0.4. This is a drastically low rate, and will result in economic and social chaos in even one generation if not eased. A more reasonable target might be one female child per couple.

Unfortunately, much of the third world is reproducing at a rate significantly greater than one. The world population growth rate is currently such that the population has been doubling about every 35 years. If we assume a 20-year generation, this is an average success rate of about 1.5, or in other words each generation is about 50% larger than the previous. The third world rate must be considerably higher than this since the industrial nations (minus certain minority groups) now have rates lower than 1. If the human density on the planet were still insignificantly small, this might be a good thing. However, we are already depleting our natural resources such as fossil fuels, water, oceanic fish stocks and everything else you can think of. Our waterways are polluted, our air is polluted, and there MAY be some increase in global warming over and above the interglacial effect due to human activity such as deforestation and production of excess carbon dioxide and methane.

What is depressing is that, although there seem to be unlimited cries for more laws against SUVs, coal fired power plants, etc., there is never a discussion or even a suggestion about reducing the human population. Doing so would not only help solve all these problems, but may well be the only long-term solution. No laws and no amount of technology can long compensate for the current rate of exponential growth of the human population on Earth. We must control our numbers or face the inevitable catastrophic reduction that reality will impose upon us. This fact especially must become a part of any intelligent discussions about subjects such as global warming, as well as contraception and abortion.

It should also be noted that, although the human female success rate is considerably greater than 1, the blue crab is obviously suffering a current female success rate significantly below 1. The friend that I referred to above recently paid over $60 a DOZEN for jumbo crabs at a restaurant near Baltimore. H. L. Mencken would be aghast.

Income Taxes, Consumption Taxes and Tariffs

Currently (April 2018) there is considerable debate raging as to the wisdom of the Trump proposed tariffs. As one more opinion on the subject, I would like to frame the argument in terms of who pays for maintaining the U. S. marketplace rather than in terms of punitive actions and retaliatory reactions in the form of tariffs.

Since the government's income in the U. S. is primarily derived from taxes, and in particular from income taxes, the government's costs of providing the infrastructure - currency, roads, courts, etc. - is paid in this country by the individuals and companies (which again boils down to the individuals) that pay the income taxes. Thus the participation in the U. S. markets by foreigners is a free ride since they do not pay U. S. income taxes. This is why U. S. made goods do not compete in both domestic and foreign markets.

The use of tariffs to level the playing field does provide a mechanism to make foreign sellers contribute to the costs of maintaining the marketplace they are enjoying, but it requires much legislation and regulation to target which goods and who's selling them. This in turn engenders hostility in those targeted and invites the 'trade wars' that are the current concern of the chattering classes. A flat tariff might be preferred in that it would be less 'in your face' to the trading partners otherwise targeted, but it still reeks of hostility to 'free trade'. It also does nothing to make U. S. goods more competitive in foreign markets.

To this author, a better solution is to replace the income tax with a National Sales Tax on all new goods. With respect to incoming foreign goods this serves the same purpose as a tariff - it makes the foreign producer pay his fair share of the support of the U. S. market. It relieves the exported goods from the income tax burden that makes U. S. goods non-competitive internationally. It allows U. S. workers to compete with foreigners as well as non-taxpaying illegals. It invites less hostility since it applies to domestic as well as all foreign goods equally. It requires no additional infrastructure to assess and collect tariffs. And as a huge added incentive, getting rid of the income tax would do more to restore health to the U. S. economy than any other single action.

Replace the income tax AND potential tariffs with a National Sales Tax. A win-win-win solution.

We Need More Growth - NOT

I have often challenged the budding young geniuses that I know with the following problem: We have been doubling the human population on Earth every 35 to 50 years for several centuries. If we had maintained that rate from the beginning, when would Adam and Eve have lived?

The current population is approaching 8 billion people, or in scientific notation, about 8x10^9. For those that have a background in digital computers, a convenient approximation is that 2^10 is just a hair more than 10^3 (2 to the 10th power is 1024, which is 2.4% more than 1000). Thus a billion (10^9 or 1,000,000,000) is 1000x1000x1000, or approximately 1024x1024x1024, which is 2^30. 8 is 2^3, so 8 billion is about 2^33. Thus the population has doubled 33 times since Adam, or 32 times since Adam and Eve.

For a doubling rate of 35 years, 32 times 35 years is 1120 years, so Adam and Eve would have started just about 900 AD. Even at a slower rate of doubling every 50 years, 32 times 50 is 1600 years, so we still could have made it to the present starting at 400 AD.

Obviously the human population growth rate has been much less over most of our history. The problem has been the growth possible in recent history due to the industrial, technological and medical advances.

Now maybe making it from 2 people to 8 billion people in 1100 or 1600 years doesn't scare everybody. But consider this: in another 1100 to 1600 years at this rate, there will be 4 billion people for EVERY ONE of us here today. It is blatantly obvious that this is not going to happen - people would be a couple miles deep over the entire planet. Even at the slower rate of doubling every 50 years, by the end of this millennium there would be a million times as many people with only 5 square feet of land or water to stand on.

Currently the human density on usable land is about 250 per sq. mile, or about 2.5 acres for each person. At current rates we would expect the population to at least quadruple over the next century, which would leave less than an acre per person. By the end of another century we're down to less than a quarter acre, and by 2300 we're down to an area of a small apartment. Remember, if you want roads, farms, malls, etc., then you have to give up part of your apartment for that.

It is the opinion of the author that we are already over a sustainable population for the planet. But even if that is not so, in very few years it will certainly be true. If we do not learn to live with stability, not growth, catastrophe is inevitable.

(c) copyright Marcus Everett, Wallback WV 25285