In a post from earlier this summer, John asked, “Shouldn’t advocates of border controls who complain about population growth leading to more crime, more welfare payments, fewer jobs, and so on, be worried not just about immigrants but also newborns?”  He noted that, unlike for immigration, very few call for government restrictions on reproduction, despite the weakness of the arguments that restricting migration is moral while restricting reproduction is not.  He concluded that government interference with both the decision to have a family and the decision to migrate should be allowed only in exceptional circumstances.

John’s post led me to consider the Baby Boom in the U.S. and how it relates to open borders.  The Baby Boom refers to the large increase in the number of births from 1946 to 1964.  Almost 80 million babies were born during these years in the U.S., making Baby Boomers the largest generation of Americans ever (if immigrants are excluded from generational counts).  When the birth numbers are adjusted for the difference in overall population sizes between the Baby Boom years and today, the results are even more impressive.  Adjusted to the 2014 population, during most Baby Boom years there were 7.5 million or more equivalent births.  For example, the population in 1953 (about 160 million) was about half of today’s population (about 318 million). There were about actual 3.9 million births that year, but that would be the equivalent of about 7.75 million births in 2014, if the ratio of births to base population from 1953 is applied to today’s population.  In most Baby Boom years, the number of births adjusted for the 2014 population exceeded the 2013 number of births (almost 4 million) by more than 3.5 million.  Please see the table below.

One observation is that the U.S. reaction to the Baby Boom supports John’s observations about generally laissez faire attitudes toward population growth through births.  Apparently there was little contemporary resistance to the Baby Boom’s production of huge numbers of humans.  Aside from eugenics programs targeting specific groups of people, such as the mentally disabled, which were adopted by many American states and which led to the compulsory sterilization of tens of thousands before, during, and after the baby boom, there appears to have been no government attempt to hinder the large number of births. There apparently also was no significant public movement against the surge of births. (I did find a contemporaneous article noting that more schools would have to be built because of the large number of births.)

This apparent lack of resistance is notable considering that, as previously mentioned, in most years of the Baby Boom more than 3.5 million additional people were being added to the population through births than are being added today, when adjusted for today’s population.  Imagine the outcry if 3.5 million additional immigrants were permitted to immigrate each year to the U.S.  It is true that even adjusting for base population, immigration levels were lower during the baby boom years than today, but this mitigates the difference in birth numbers only slightly.  (As the table shows, the difference in the overall population growth during the Baby Boom years and today (0.77%) is even more significant than the difference in adjusted birth numbers.)

A second observation is that the positive impact of the Baby Boom provides additional evidence that fears of swamping by large numbers of new people under open borders are unwarranted. The economist Peter Yoo looked at the economic impact of the Baby Boom on the U.S. economy.  Using economic models, he apparently found a positive impact: “… after a period of slow growth, per capita consumption increases.  Best of all, the models indicate such improvements in the standard of living occur as even aggregate savings drops.”  This finding echoes evidence that significantly increasing a host country’s population through immigration can have neutral or positive long-term economic outcomes.  It is notable that immigration has an advantage over reproduction from an economic standpoint, since a large portion of immigrants are ready to enter the workforce and contribute to the economy, whereas people born into the economy are dependent for many years before entering the workforce.

A related observation is that without population growth, whether through immigration or births, countries tend to founder. Jonathan Last, author of What To Expect When No One’s Expecting, states that “… growing populations lead to increased innovation and conservation… Low-fertility societies don’t innovate because their incentives for consumption tilt overwhelmingly toward health care. They don’t invest aggressively because, with the average age skewing higher, capital shifts to preserving and extending life and then begins drawing down.”  He suggests that low fertility rates in Japan account for the country’s economic slowdown in recent decades.  Similarly, the U.S., with a fertility rate below the replacement level, faces decline, he believes.  Since Latin America is experiencing fertility decline, Mr. Last doesn’t believe that immigration can compensate for low fertility in the U.S., although it seems unlikely that the desire to migrate from Latin America to the U.S., or from any number of other poor countries throughout the world, will diminish any time soon.  Immigration appears to be an easier way to maintain population growth than attempting to persuade U.S. citizens to have more babies; Mr. Last notes that, aside from the Baby Boom, throughout American history the fertility rate “has floated consistently downward.”  An open borders policy, of course, would facilitate the immigration needed for population growth.

One downside of population growth is that it further strains the environment, as Philippe Legrain has pointed out.  Another is that if the growth later slows, the ratio of the number of retired people to those working increases.  This is a concern about the retirement of the Baby Boomers.  Given America’s low fertility rate and that people are living longer, Mr. Legrain states in Immigrants: Your Country Needs Them that in order to maintain the 1995 ratio of working people aged 15-64 to people 65 and older, about 11 million immigrants per year would have to enter the U.S. through 2050.  (Immigrants tend to be younger than citizens of receiving countries.)  Since immigrants age too and since they probably would not have enough children to maintain the ratio, Mr. Legrain suggests that this would be “only a temporary fix” to an aging population.  However, he also suggests that combined with raising retirement ages , increasing saving rates, and higher taxes, immigration can help the U.S. deal with an aging population.  (See here for a  discussion of the impact of immigrants on the Social Security system.)  Plus, echoing Mr. Last’s connection between growing populations and innovation, Mr. Legrain adds that”if immigration also helps spur productivity growth, it will increase the size of the economic pie available to everyone.” (p. 160)

Vipul suggests that high numbers of immigrants could reduce host country birth rates by driving up the cost of housing, with its cost inversely related to birth rates.  This would weaken the positive impact of immigration on the aging problem.  However, it seems that a larger number of immigrants would be an improvement on the status quo, despite some resulting decrease in native births.

Without the Baby Boom, the U.S. may have suffered economically due to population decline.  Since another similar surge in births is unlikely, immigration, paired with policies to address larger numbers of older residents, will be a key component in maintaining America’s vitality by providing population growth.  An open borders policy would help ensure this population growth.