1. High-quality studies—including one on Cambridge’s rent control—show that while remit benefits existing tenants, it has large negative effects on other people (including those who are also low-income). It reduces rental supply, which in turn exacerbates the affordability and accessibility problem it intends to solve. Summary of academic literature: https://www.brookings.edu/research/what-does-economic-evidence-tell-us-about-the-effects-of-rent-control/

2. It can be helpful to frame this in causal terms. What will happen to existing residents of mixed-income neighborhoods near Boston if additional housing is built? Now suppose everything else is identical, except you do not build additional housing. What will happen to the residents of mixed-income neighborhoods? Middle and high-income demand to live in the Boston metro area is there in either case. Therefore, relative to the counterfactual of building more housing, restricting new supply increases rents and leads to more displacement of existing residents. Sources: https://www.sciencedirect.com/science/article/abs/pii/S0094119021000656, https://direct.mit.edu/rest/article-abstract/doi/10.1162/rest_a_01055/100977/Local-Effects-of-Large-New-Apartment-Buildings-in

3/4. As you can see by looking around town, it’s currently more profitable in many places to build lab space than new housing. The policies you’re suggesting make housing relatively less attractive to build, so they would likely hurt housing supply and increase prices that most people pay. These do benefit the low-income beneficiaries lucky to get them, so it’s not entirely unreasonable to do this in conjunction these with other policies that make building more housing feasible and attractive.

5. Policies that make building more housing feasible and attractive include zoning predictability and greater density. Zoning predictability means laws with clear requirements that allow developers to quickly break ground without costly delays and litigation. Greater density can be achieved by relaxing various zoning requirements: allowing taller heights; larger floorspace-area ratios; fewer minimum parking requirements (both for residential and commercial properties; smaller minimum lot sizes; smaller setback requirements, allowing accessible dwelling units; and allowing duplexes, triplexes, or other forms of multi-family housing rather than mandating single family homes.