The cover story inThe Economist this week predicts that population will peak this century:

Last year the United Nations said it thought the world’s average fertility would fall below replacement by 2025. Demographers expect the global population to peak at around 10 billion (it is now 6.5 billion) by mid-century.

This peak is only temporary. Fertility plotted vs. money income is U-shaped. Poor can’t afford family planning, but the rich want to have kids.

They further opine:

States should not be in the business of pushing people to have babies.

Yes they should. A baby will become a taxpayer and a useful citizen. Zero population growth did far more to hold back development of China and India than Reagan’s (anti-) family planning policies.

We can grow food indoors, reuse our water and get the energy to do it from carbon free sources. The carrying capacity of the Earth is easily one trillion people. At the current rate of waste heat per person, we would be generating only 2% of what we get from the Sun. We could site 72 billion at the density of the Netherlands, 3.8 trillion at the density of Manhattan with the current land area.

A populous world is a rich world. There will be greater grand challenges that can be tackled. There will be more people to conceive more ideas. A world with one trillion people at the current standard of living would have GDP of $10,000 trillion or $10 quadrillion dollars a year. If 0.2% of that was spent on space exploration that would be $20 trillion/year. At $20,000/kg, that’s enough to lift one billion kg. At $200/kg, that’s enough to allow one billion people to emigrate to space every year.

A populous world can be the Garden of Eden to settle a harsh solar system and galaxy.

What policy should be used to achieve higher population? I shun family planning restrictions. Greater credit and liquidity would be a good start. Letting families borrow at subsidized rates to support kids would be sensible. It’s a natural extension of our education policy to offer loans to create skilled labor. Since the government has better credit than the typical set of new parents, the program can be run at a profit before taking into account its effect on growth.

If national accounting were modified to capitalize future tax revenue based on population, then policies that encourage the birthrate (and immigration) would arrive at Congress as a way to “pay for” favored programs. In fact, increased birth and immigration rates will reduce the national debt per capita even faster than in total. Changing the budget rules so that the debt ceiling is per capita based on the anticipated population would be even more effective.

Some targeted policies would be the following:

• Turn the dependent exemption for children into a credit and not phase it out for high earners and payers of the alternative minimum tax
• Subsidize day care with a credit, instead of a deduction
• Raise the estate tax on childless people
• Subsidize treatment of infertility
• Pay a bounty to parents whose kids graduate
• Pay 10% of lifetime tax revenues of kids to each parent

Simply making the country more attractive through better policies will increase the birthrate.

The best The Economist can come up with is urban planning, higher retirement age and opening of the labor force to women.

No. If citizens of Japan (and the US) want their cultures to thrive, they must open their doors to immigration and use their genius industrial and tax policies to grow the most important resource they have: their population.