When policymakers want to help people with low incomes get a mortgage, they typically offer some kind of subsidy or boost the flexibility of the underwriting guidelines.

This week, the Federal Home Loan Bank of San Francisco will pioneer a radically different approach: It will try to turn more Americans into homeowners—not by giving them a break but, instead, by catalyzing the creation of good jobs in their communities.

“What we’re doing is getting at the root cause” of why buying a house remains out of reach for many families, says Larry Parks, the senior vice president of external, legislative, and regulatory affairs at the bank, a cooperative that gives its member financial institutions inexpensive loans and risk-management tools so that they, in turn, can increase the availability of mortgages and stimulate community development. “We’re changing the thought process.”

At the center of it all is a Quality Jobs Fund, which the bank established after years of research and rumination by donating $100 million to the New World Foundation.

New World will disburse money from the fund to nonprofit and for-profit “intermediaries” that promise to spur employment in areas that badly need it. The foundation will identify and select these organizations. They include job-training programs, social enterprises that aim to improve economic opportunities in disadvantaged neighborhoods, and entities that foster employee ownership.

The first payout will be formally announced on Friday: $5 million to the Central Valley Fund, which provides capital to small and midsize businesses, mostly in poorer and…