A new analysis by Redfin economists has found that the share of listings that the median-earner could afford in Massachusetts’ two biggest metros has fallen nearly 60 percent or more over the last year.

Between a steady upward march in prices and big jumps in mortgage rates – Freddie Mac put the average rate on a 30-year, fixed-rate loan at 6.65 percent last week – Greater Boston and Greater Worcester saw big hits to their housing markets’ already-strained affordability.

“Housing affordability is at the lowest level in history, which will widen the wealth gap – especially between Millennials,” Redfin Deputy Chief Economist Taylor Marr said in a statement. “Many Millennials were able to buy their first home before or during the pandemic homebuying boom, but many others were priced out of homeownership and forced to keep renting. That means a lot of young adults missed out on a major wealth building opportunity: the value of homes owned by Millennials has risen nearly 30% in the past year.”

In Greater Boston, the share of listings a household making the area median income could afford – defined as a monthly payment not exceeding 30 percent of their wages – fell 66.7 percent, from 22.9 percent of listings in 2021 to just 8.7 percent in 2022.

That put Boston at 27th place in the ranking of least-affordable markets in the country, in the company of communities like Providence, Rhode Island, Phoenix, Arizona and Colorado Springs, Colorado.

In the Worcester market, the share of affordable listings dropped 59.2 percent, from 45.8 percent of homes for sale down to 21.1 percent.

“The good news is that housing affordability should improve,” Marr said. “Mortgage rates will eventually come down as the Fed makes progress fighting inflation, and home prices have already begun falling. Incomes are also growing faster than the historical norm.”

Redfin’s analysis also uncovered troubling shortfalls in who can afford to buy a home these days. Only 2.2 percent of Boston-area listings last year were affordable the median Black household, versus 3.2 percent of listings affordable to the median Latino household, 11.2 percent affordable to the typical white household and 20.1 percent of listings affordable to the median Asian household..

The median Black household could only afford 11.2 percent of Worcester-area listings last year, compared to 3.6 percent for the typical Latino household, 25.5 percent for the typical white household and 32.1 percent for the median Asian household.

“Housing has become incredibly unaffordable for a lot of Americans, but Black families have been hit especially hard because they’re often less wealthy to begin with,” Redfin Chief Economist Daryl Fairweather said in a statement. “On average, Black Americans earn less money, have less generational wealth, and have lower credit scores (and sometimes no credit scores at all) than white Americans. That makes it tougher to afford a down payment and qualify for a low mortgage rate. They also frequently face racial bias during the homebuying process.”