But because ours is no longer an agricultural economy, and because most people apparently prefer to live in densely populated cities and suburbs, population density per-square mile of geographic space is less significant than it at first appears. A more relevant statistic is residential living space. Here too, our ability to “absorb” immigrants is much higher than in 1920. In 1920 the amount of residential floor space per person in the US was 242 square feet; today (2014) each American has, on average, 1,046 square feet – more than four times as much as a century ago.
What about food? Crop yields today are much higher than in 1920. For example, wheat yields have tripled and corn yields have quintupled. This increase in agricultural productivity has reduced the real price of food. In turn, the percentage of Americans’ total personal income spent on food has fallen dramatically.
Let’s look at some other goods and services that might be relevant for assessing America’s current ability to “absorb” immigrants compared to its ability to “absorb” immigrants just before quotas were imposed.
- Petroleum In 1920 America had 7.5 billion barrels of proved reserves; today (2023) America has 68.8 billion barrels. On a per-capita basis, for every American in 1920 there were 71 barrels of proved petroleum reserves, while in 2023 the number of proved reserves per American is 202.
- Teachers in primary and secondary schools In 1920 America had 1 teacher for every 32 pupils; today America has 1 teacher for approximately every 15.5 students.
- Physicians In 1920 the number of physicians practicing in America was 144,977, or one physician for every 731 Americans. The number of physicians practicing in America today is 1,077,115, or one physician for every 316 Americans.