DEMOGRAPHIC  CHANGES have accelerated in Boston and elsewhere in recent years.  There has been an increase in healthy older people who may no longer want to live in single-family housing and worry about “SST”—snow, stairs, and trash. These Boomers are too young to live in assisted living and usually too affluent to qualify for any subsidized housing. At the other end of the spectrum, our cities are full of 20-somethings who are no longer eligible to live in the cocoon of a dormitory, yet still crave the convenience and novelty of the college experience, best approximated by urban living.

An oft-ignored (and shrinking) third group consists of young couples with children, who seek housing with access to transit and open space. The last of these groups is being disserved by antiquated zoning codes, which send them the message that they are not necessarily welcome in our cities. We believe this must change and that people in Massachusetts can learn from other states.

Zoning is and has long been a mainstay of urban life: The Supreme Court’s Euclid decision upholding zoning in the face of constitutional challenges was rendered almost 100 years ago.

Sadly, zoning was used to discriminate against black people and other people of color, both as a result of acts of omission and commission on the part of various governments.  Soon after being admitted to the Massachusetts bar, one of us (DiCara) was appalled to find racial covenants in deeds in his home neighborhood of Dorchester.

All of these, thankfully, have now been rendered null and void.  Zoning targeted disfavored religious groups, as well: Communities often made it difficult for a Catholic church or a Jewish temple to be constructed within their borders. These practices occurred even in the enlightened Boston suburbs in the years during and after World War II, until being cured by the Dover Amendment in 1950.

When a government legislates to incentivize or discourage behavior, it is effectively sending a message to its citizens about its values and priorities. In some jurisdictions, it is easier to vote than in others. Jurisdictions that make it easier to vote signal their belief that democracy should be inclusive and participatory, while those that discourage it signal that political participation is reserved for particular groups.

We traditionally have had deductions for charitable giving, expressing the principle that philanthropy should be encouraged. Taxation is also a form of messaging. Until recently, Americans have enjoyed unlimited state and local tax deductions. President Trump’s discontinuation of that policy sends a clear message to people living in places like Massachusetts—people who tend not to vote for the President or support his policies—by penalizing them through tax reform.

Where gas taxes are high, they are often used to subsidize public transportation. In states where gas taxes are low, public transportation tends to be disfavored and underdeveloped.  Each of these policies embodies a strong message.

In no area, however, is messaging more predominant than in zoning. Some years ago, the two of us proposed some zoning changes for parcels surrounding the Indigo Line – a railroad line that is a straight shot into downtown through some of Boston’s most challenged neighborhoods. We suggested treating those parcels differently than parcels farther away in order to maximize their development and provide ridership for the commuter rail line.

Our idea would be a modern-day version of the story told by Sam Bass Warner in his 1962 book Streetcar Suburbs, which delineated the direct relationship between the development of Dorchester, Jamaica Plain, and other neighborhoods and the availability of streetcars following the Civil War.

Current zoning varies across the nation. Once again, messaging is involved.

Urban planner Nolan Gray and research fellow Lyman Stone point out that the Philadelphia City Planning Commission recently considered a proposed zoning change “that would effectively ban new day care centers – along with tire stores and car repair shops – in a large chunk of northwest Philadelphia.”  This messaging parallels that which is often found in affluent suburbs, where roadblocks are put in place of construction of affordable housing, even as some of the residents of these same communities may be active proponents of affordable housing elsewhere.

Residential zoning in Boston and other cities is structured to maximize tax revenue. Children (and the elderly) earn little or nothing, yet often cost a great deal in terms of services. Childless adults—whether “empty nesters” or those without children—are prime earners who typically need comparatively fewer resources.

Four years ago, one of us (DiCara) coauthored an article for CommonWealth entitled “Kid-Free Boston” with James Sutherland and Sam Adams, which described the dramatic decline in the city’s population of school-aged children. The article referenced a recent essay in Governing magazine by Alan Greenblatt, “Do Cities Need Kids?” which reported that nearly half of all young families in Seattle moved to suburbs once their children reached school age.

Smaller units, sometimes called micro-units, are really only appealing to the childless adult population – the very young who need a halfway step after living in a dormitory, and older empty nesters who seek to live in what we refer to as “unassisted living,” where they don’t worry about much of anything and yet do not need significant services.

Given these factors, it should come as no surprise that zoning incentivizes the efficient, micro-studio and one-bedroom units that attract those in these coveted groups and effectively bars those with children. But is this a message we are comfortable with our government sending?  Shouldn’t Boston reject so-called “vasectomy zoning”?

We believe that zoning reform is in order to provide housing options for those who need it. We also think Boston should reverse much of the downzoning that occurred in the 1980s, which has rendered many projects effectively unbuildable.

Boston could follow the example of many cities and states that have expressed their interest in change via legislation. Recently, Minneapolis passed “Minneapolis 2040,” a comprehensive development plan that promotes density around transit hubs and eliminates single-family-only zoning.

Certainly, this will increase the supply of housing and arguably stabilize accelerating rents by increasing supply.  The vote of the Minneapolis City Council aims to “eliminate racial disparities, fight climate change, increase transportation options, and improve access to jobs,” according to an account of the planning effort. The same article suggests the city’s old, single-family zoning is a holdover from the 1960s and points out that “urban planners have since criticized single-family zoning for fostering segregation and enabling urban sprawl.”

Portland, Oregon, is looking to allow four-unit buildings in single-family zoned neighborhoods, which is anticipated to add over 24,000 new homes to the area. Seattle’s affordable housing crisis, fueled by having 75 percent of residential land zoned for single-family housing, has spurred its leaders to consider similar fixes.

Legislative bodies and communities establish their values through legislation. What is the message if our laws discourage families with children from living in our cities? Do we accept the new reality that cities should be the home of only the comfortable people without children and the permanent poor?

In other jurisdictions, there is talk of mandating multifamily housing around transit nodes. This is a step beyond the opt-in Chapter 40R zoning, which Massachusetts passed a decade or so ago to spur similar changes but which, sadly, has never lived up to its expectations, given the reluctance of so many communities to take advantage of its incentives. Should the incentives become mandates? If a city makes it easy for there to be micro-units close to train stations, but does not incentivize (or even allow) in the same neighborhood units where children can live, nor provide any playgrounds, baseball fields, or basketball courts, then in fact the message is loud and clear that children are not welcome.

We would suggest that, going forward, all jurisdictions provide zoning options for all citizens.  We should not ghettoize old people, we should not ghettoize poor people, and we should not exclude people with children.

Lawrence S. DiCara is an attorney and former Boston city councilor. Conor Ahern is a staff attorney for the New York City Commission on Human Rights.