PAST PERFORMANCE IS NO GUARANTEE OF FUTURE RESULTS: This is the real doom loop. It will change everything about life in the Bay Area.

The Bay Area is facing a doom loop. It’s just not the one we usually think about.

For years we’ve heard of the potential economic doom spiral circling San Francisco, where a massive city budget deficit fueled by remote work leads to poorer services and even more residents fleeing. But another threat has been building in relative silence.

The Bay Area is getting old fast, and it’s accelerating. Though aging is a global trend, the San Francisco metro area — which includes San Francisco, Alameda, Contra Costa, San Mateo and Marin counties — is already the third-oldest among 20 of the largest regions in the U.S., trailing only two places in Florida. And no other region is growing older at a quicker pace.

That means fewer children, more elderly people and a declining number of 20-somethings. The confluence of demographic shifts will profoundly impact every aspect of life in the San Francisco area. Combined with rising housing costs and growing hostility toward immigration, the graying of cities and towns means the region’s continued prosperity is in doubt.

—The San Francisco Chronicle, yesterday.

Perhaps that’s because Chronicle readers took the newspaper’s advice on the topic. In 2008, the paper was complaining that “There is nothing more bacchanalian than a kid’s birthday party,” and how those bacchanalian birthday parties lead to increased global warming, from their perspective, those declining numbers were good news, right?

In 2013, the San Francisco Chronicle reported that San Francisco has the lowest percentage of children of any major American city:

Just 13.4 percent of San Francisco’s 805,235 residents are younger than 18, the smallest percentage of any major city in the country. By contrast, San Jose’s percentage of children is 24.8 percent, Oakland’s is 21.3 percent, Boston’s is 16.8 percent and Seattle’s is 15.4 percent, according to Brian Cheu, director of community development for the Mayor’s Office of Housing. Even Manhattan is composed of roughly 15 percent children, according to Dan Kelly, director of planning for San Francisco’s Human Services Agency.

In 1970, children made up 22 percent of San Francisco. In 1960, they constituted 25 percent.

I’d say there is a glimmer of hope for the city based on this Wall Street Journal headline, “Mayor Daniel Lurie: ‘San Francisco Needs to Save Itself.’” But “unexpectedly” the word “homeless” doesn’t appear until the comments section.

(San Francisco’s last Republican mayor left office at the beginning of 1964.)