Working-class people are being priced out of major cities all over America. But the effect is particularly pronounced in the Bay Area with San Francisco, San Jose, and especially Oakland shedding citizenry at rates leaps and bounds ahead of the likes of New York or Chicago.

That’s the news from Mark Uh, a data scientist with real estate site Trulia, who spent some late nights with a whole lot of census data to calculate the migration patterns out of 10 major cities over a four year period starting in 2010.

The numbers tell a startling but predictable story, as working people and young people seem to be getting squeezed out.

In San Francisco, for example, households earning $30,000 or less a year or less made up only 12.4 percent of the initial population, but were 19.7 percent of people who opted to leave town. Those earning $60,000 a year were 29.5 percent of the initial population, but made up 43 percent of those who left.

The effect is even more pronounced in the greater Bay Area: In Oakland, households making $30,000 a year were 14.6 percent of the initial population, but were 28 percent of those who moved away during the four-year period.

Numbers like that should surprise no one keeping tabs on the housing market, although Uh’s report doesn’t speculate about the cause of these migrations, nor whether they reflect people leaving by necessity or choice.

Oddly enough, San Jose is much harder on those in the slightly higher income bracket: The capital of Silicon Valley had the highest move-out rate for households earning around $60,000 a year, which comprised nearly half of all move-aways.

Despite the popular image of the young, moneyed techie saturating the city, Trulia’s number crunching also showed that it seems to be increasingly hard for millennials age 18-34 to stick around. That age bracket was 27.4 percent of San Francisco’s population, but 52.3 percent of those who left.

While that’s a huge spike, it’s actually the lowest among all the cities surveyed. That probably means that while startup jobs do indeed make it easier for young folks to afford the city, the market is still too hot for most to handle.

Across all cities, those most likely to leave are residents in the military and those working in agriculture, although the sample size of both groups is pretty small. The trades with significant populations that seem to have the hardest time sticking around are, of course, retail and the arts.