Two months ago, Gov. Maura Healey declared a state of emergency due to the severe lack of shelter availability in Massachusetts, coinciding with a rising number of migrant families arriving. In some circles, this combination was described as an immigration crisis, but it’s really a crisis caused by our long-standing shortage of housing.

In much earlier periods of high immigration, new arrivals often had to share a home until they got jobs and could afford their own. When the existing supply of housing became inadequate for the growing population, enterprising homebuilders could produce more. Around the turn of the 20th century, parts of Cambridge saw single-family homes “replaced by multifamily types, providing inexpensive suburban housing along the streetcar lines for families of modest means,” according to a Cambridge Historical Commission study.

Today, Cambridge’s housing opportunities are radically more limited. Most of our classic triple-deckers and other still-popular multifamily structures are many decades old, but more of them cannot be built today because they don’t comply with our zoning laws. Our city’s growing population is colliding with decades of insufficient housing production and zoning laws that say “No!” far more often and effectively than they say “Yes.”

Our current housing shortage oppresses and displaces not only recent immigrants, but low- and middle-income households generally. Those who pay rent for their homes are especially vulnerable to housing costs that have been rising faster than wages. The shortage has made Greater Boston’s housing costs among the highest in the country. Even employers, public and private, are feeling the pain.

While Cambridge has a long tradition of welcoming immigrants and lifting up people without financial means, a major discrepancy between our values and our laws impairs our ability to meet the challenges of gentrification, displacement and climate change. Generally, most Cambridge hearts are in the right place, but they’re undermined by Cambridge’s zoning laws and procedures. This disparity was originally built upon the nation’s long history of racial bias but – after many court decisions and national and state laws eroded that foundation – is now more usually based on differences in economic class.

This problem is certainly not Cambridge’s alone. Many communities’ original zoning laws, from the early 20th century, drew on older laws about “nuisances.” Emily Badger, who investigates the connections between housing, transportation and inequality for The New York Times, provides nationwide examples when she reports that “nuisance laws had targeted problems like noxious odors or chemical spills that crept across property lines. Zoning, rather than punishing people for proven harms that came from their property, told people what they could do on their property in the first place. And it prohibited many things – like buildings of a certain height – that had never been considered nuisances before.”

“Our homes have become our wealth,” Badger noted. “Racial fears linger even if they’ve become encoded in other language. Change invariably looks like a threat. And the universe of threats has broadened from the toxic spill to the garden shadow, from the property next door to the potential development five blocks over.” Cambridge conservatives who see change and growth as threatening often use appeals based on “neighborhood context” or “historical character” to make their case.

Over time, some of Cambridge’s neighborhood-based and policy-advocacy groups have played key roles in constructing and maintaining the unjust and damaging gap between our values and what we expect our city government to do.

“Neighborhood Defenders: Participatory Politics and America’s Housing Crisis” (summarized here) was researched and written by three Boston University faculty members who drew many of their examples from Cambridge and nearby communities. They found that “neighborhood participation in the housing permitting process exacerbates existing political inequalities, limits the housing supply and contributes to the current affordable-housing crisis.”

Using a database of residents’ comments at public hearings, the authors found that just under 10 percent referred to the local land use restrictions on which a board’s decision to grant or deny a permit are supposed to be based.

The authors also report that public hearing commenters “hold overwhelmingly negative views of new housing – far more negative than their broader communities – and are socioeconomically advantaged on a variety of dimensions. Using land use institutions, these individuals – who we term neighborhood defenders – are able to raise concerns that lead to lengthy delays, high development costs and smaller projects. The result is a diminished housing stock and higher housing costs.”

The Harvard Square Defense Fund was a prime example of the role of “neighborhood defender” organizations and their sometimes unintended consequences. From about 1979 to 2008, HSDF members worked vigorously to keep Harvard Square the way they preferred. They sued to block any buildings whose design they disliked, and targeted proposals for restaurants selling low-cost fast food – which were usually franchises operated by local businesses, often immigrant-owned or minority-owned.

HSDF’s designated successor has continued to resist changes in Harvard Square, including opposition to much-needed zoning reform (2019) and an attempt at blocking a permit for a minority-owned cannabis dispensary (2021). The combined effect of residential zoning’s upward push on housing costs and wealthy residents’ disdain for businesses not in keeping with their own idea of the Square’s “character” has resulted in a thorough – and thoroughly unpopular – commercial gentrification of the Square.

In the best traditions of the old, “political” Harvard Square, the students on the Harvard Crimson’s editorial board have connected the dots, noting that “in one of the most liberal cities in America, low-income residents and low-price businesses have found themselves victims of a wealthy gatekeeping policy – one with disproportionate negative effects on unhoused residents, whose housing insecurity is overwhelmingly due to rising rent prices in the city.”

Reviewing this history is particularly important right now, when the Cambridge Charter Review Committee is reconsidering the basic structure of our city government and another municipal election season is underway. The Boston Globe has just reported (again) that our city, “where nearly 70 percent of residents rent – has become shockingly expensive to live in.”

The Globe notes that our efforts to deal with the housing crisis are reviving “long-standing political tensions” and putting our “ideals to the test,” while reporting that some candidates for City Council would rather appeal to preferences heard among the home-owning minority who are using the mere existence of dissent to defer action on a growing crisis. This is indeed the time to consider the direction that our policies and laws will take.

It’s been a century since Massachusetts granted zoning authority to our city and town governments, and more than a half-century since the Legislature passed the first of many tries at reining in local communities’ abuses of that authority. It has taken us many decades to journey from “As long as they don’t move next door” to “Not in my backyard,” although the actual distance between them is not very great.

James Zall, Pemberton Street

James Zall is a longtime resident and a homeowner.