Declining birth rates have been in the news lately, and most of the reporting I've read has centered around the resulting demographic shift causing economic difficulties. While I'm sure there will be economic difficulties to overcome, I think it's necessary to do so, and now is a better time than later.

An economy that requires a continuously increasing population is not sustainable indefinitely. Eventually, we'll have enough people that we need more of some resource we don't have a good way to get more of and be forced into the sorts of decisions that form the basis of dystopian sci-fi. That people are voluntarily having fewer children solves the problem before it becomes a crisis.

Fewer people means that each person can have a larger share of limited resources. Each person's labor becomes more valuable due to reduced competition, which is well-timed as automation reduces the demand for low-skill, low-pay labor. Of course owners of businesses that currently profit from inexpensive labor might not be thrilled about it, but as long as the world still has people living in extreme poverty, I suspect there are ways to fill any remaining demand for cheap labor.

Deltas:

• Sperm counts have been dropping continually in western men for decades, so reduced births aren't necessarily voluntary. While there are some solid suspects, we don't know why for certain, and that's scary.
• Too much of a good thing is possible, and Japan may have it with an exceptionally low birth rate and a low immigration rate leading to no viable way to support its elderly.
• There is an education bottleneck for nursing in the US, resulting in a shortage that will only get worse as the population ages unless solved.