The San Francisco Budget and Legislative Analyst’s office released a report Tuesday indicating that the city would have needed to add some 459,000 units over the past 30 years to bring housing prices down to national trend levels.

Should current trends in the types and quantities of housing built continue, the report also says, the Mission will only be 31 percent Latino by 2025, and high earners will continue to replace low income families leaving the neighborhood.

Supervisor David Campos commissioned the report after a September report by the city’s chief economist Ted Egan indicated that the proposed Mission moratorium would have no effect on the neighborhood’s evictions because most newcomers arriving in the Mission have moved into existing housing stock rather than new units. Egan also concluded that the moratorium was likely to raise rents around the city by a few dollars a month for new renters.

“This report is a counter to the very one-sided, very narrow perspective that was presented earlier,” Campos said.

Critics and housing activists have argued that demand for housing in the neighborhood is so great that building enough housing to satisfy that demand is untenable.

Campos said catching up to a 400,000 unit deficit is unfeasible and compared it to building “another city the size of San Francisco on top of San Francisco.” The city’s current housing stock comes to about 380,000 units.

Instead,  he expressed support for the 18-month moratorium on market-rate housing in the Mission that would be enacted by Proposition I. 

He and other moratorium supporters emphasized the need for affordable housing, which is in short supply in the city’s pipeline compared to market-rate housing. The city is falling far short of its goal to build 30,000 new housing units by 2020. In 2014, the city added 3,514 new units 21 percent of which – rather than the stipulated 30 percent – were affordable. In the Mission, 627 units were added between 2010 and 2014, only 9.6 percent of which were affordable.

“Who can live in this city with dignity that’s working-class?” asked Lariza Dugan-Cuadra, the executive director of the Central American Resource Center who was evicted from her Mission District home.

“We need to stop displacement,” said Maria Zamudio, an organizer at the tenant advocacy organization Causa Justa::Just Cause. “This report shows clearly that more market rate development is only going to exacerbate this situation.”

The report makes no claims about whether the city should build at a higher rate than it currently is.

It would be a very radical change in the level of construction in San Francisco, and ultimately to get to the needed numbers, a radical change in the city itself in terms of its density and population,” said Frank Brusseau of the Budget and Legislative Analyst’s office. “I’m not sure, given our current set of land use regulations, that it could be done or that it’s desirable on the part of the community and the policy makers.”

Development proponents, for their part, interpreted the housing shortfall as a reason to build more aggressively.

“There is a path to affordability. It involves a tremendous amount of units,” said Sonja Trauss, who heads the Bay Area Renter’s Federation. Where Campos and housing advocates see an impossibility, she sees a simple solution.

“Instead of saying no, say yes,” Trauss said.  “There are people all over the city that, all they wanna do is build stuff. They come to the city and say, can we build? And the city says, I dunno, no? And then the city says, how can we build?”

But to moratorium advocates, it’s the type of housing built that matters, and the preservation of the character of the Mission.

The Budget and Legislative Analyst’s Office also noted a 6,000-person decrease in Latinos in the neighborhood, along with a net population decrease of  almost 4,000, which the report attributed  to a reduction of the number of families in the neighborhood. Units are still occupied by multiple people, but they tend not to be related.

Those changes are due, said Roberto Hernandez, to a lack of affordable housing.

“San Francisco has failed to put together a comprehensive plan for affordable housing,” Hernandez. Under a moratorium, he said, funding for affordable housing should come from property taxes on newly developed housing and from taxes on Airbnb.

“Where will we get the money? Let’s look at Airbnb. They’re finally paying taxes, right? You saw all the billboards about how the money should be spent,” Hernandez said, referring to backlash over the home-sharing platform’s controversial ads.

According to Leticia Hernandez (no relation to Roberto), the Mission is “not dead, not resigned.”  Instead, she said, “there is a war waging.”