Ironically, population losses in older cities result in great measure from increased opportunity and wealth. In even the poorest areas, many children eventually are able to leave their neighborhoods for better ones. Lower household population ratios and abandoned housing are the result. In any event, a city’s population per se is unimportant. What counts is its wealth and quality of life, and by these measures the District may someday again exceed its neighbors.

Chevy Chase, Md.