Segregation. Homelessness. Income inequality.

A new Boston Foundation report finds nearly all these things are getting worse in Greater Boston — and, to a large extent, they all trace back to housing.

Study author Alicia Sasser Modestino says the state’s practice of giving cities and towns control over how land is developed bears much of the blame.

She says this "home rule" tradition allows municipalities to erect barriers to the construction of housing.

"I think in New England we have a long tradition of thinking that home rule is a right and not acknowledging that it can sometimes work to the detriment of the greater good," said Sasser Modestino, associate director at Northeastern University's Dukakis Center for Urban and Regional Policy. The report was also done in collaboration with UMass' Donahue Institute and the Massachusetts Housing Partnership.

On top of not helping meet a growing demand for housing, Sasser Modestino says some local planning and zoning boards are contributing to segregation by refusing to allow certain kinds of development.

"We find very explicitly that communities that built a greater share of multifamily housing per capita saw a decrease in racial segregation," she said. "It’s not just, build more [luxury and single family] housing and we’re gonna address the segregation issue. ... It's really about building different types of housing and affordable housing in those suburban communities. That's going to move the dial."

Much of the conversation on affordable housing in Massachusetts revolves around a law known as Chapter 40B. It allows developers to skirt local zoning control in order to build affordable housing — but only until 10% of the community’s housing stock is affordable.

The law has had big repercussions in places like Boxborough, northwest of Boston, which has a population of 5,700 and median income of $116,000.

Selectman Les Fox says a proposal for a large 40B development in the late 1990s caused residents to worry it would overburden the school system. That drove the town to take a serious look at the need for affordable housing — on its own terms.

"The sense was that to do something about affordable housing so that we addressed the housing needs and ... not have this situation happen again, where something is going to happen that we didn't want to happen,” Fox said.

The town ended up purchasing the land and the development never happened. What did happen was the formation of the Boxborough Housing Board to oversee the production of affordable housing, as well as other mechanisms aimed at helping low-income residents have a home.

Now, according to the Boston Foundation report, Boxborough’s affordable housing output leads the 19 communities that are doing more than their “fair share."

(Courtesy of the Greater Boston Housing Report Card 2019)

Fox says there’s a general sense in town that residents want to address income inequality by providing a place for people to live — especially the kind that integrates people of different economic strata.

"You could be living right next door to somebody whose apartment looks exactly the same as yours but they're paying less rent because that's a deed-restricted unit and [the landlord] runs it for less money," he said.

But Boxborough is an outlier. Only 30% of Greater Boston’s cities and towns have reached the 10% threshold for affordable housing that was set in the 40B law, which has been on the books since 1969.

Now the Boston Foundation and its partners are calling for a shift away from the home rule order, and for the state to impose less restrictive zoning on local communities.

That could include allowing single-family homeowners to build in-law apartments without jumping through hoops, or it could mean requiring municipalities to adopt zoning for multifamily housing.

If these changes don’t happen, they argue, it could be impossible to meet the Boston area’s growing demand for housing.