New York City had rent controls since 1920
Not true. In 1920, New York adopted Emergency Rent Laws, which effectively charged the courts of New York State with their administration. When challenged by tenants, rent increases were reviewed by a standard of "reasonableness." The definition of reasonableness was subject to judicial interpretation. Certain apartments were decontrolled beginning in 1926, and the Rent Laws of 1920 expired completely in June 1929, although limited protections against evictions considered unjust were continued.
In the post-war period rent controls were in operation in many American cities. By reducing the return to landlords it made sense for them to let their properties go to rack and ruin. This was a major source of ‘urban blight’. As the economist Assar Lindbeck put it, “In many cases rent control appears to be the most efficient technique presently known to destroy a city—except for bombing.”
So strong is the evidence for this that we have that rarest of things – a consensus among economists. In 2012, economists were polled with the following question;
Local ordinances that limit rent increases for some rental housing units, such as in New York and San Francisco, have had a positive impact over the past three decades on the amount and quality of broadly affordable rental housing in cities that have used them.
81% of them disagreed.
81% of economists agree that rent controls are bad policy
So, you are among the 19%.