In a city like New York, there are many "unregulated apartments." With these types of units, landlords aren't restricted with respect to how much they charge to lease an apartment.
They're also not limited to how often or how much they choose to increase rent. They can increase rent on a whim whether the market dictates that it's necessary or because they actually intend to make improvements to the building they own.
With unregulated apartments, landlords are additionally allowed to pick and choose to whom they want to rent their apartments. Even without having a valid reason, they can inform tenants that they don't have any intention of renewing their leases. If they do, and the tenant refuses to move out within a reasonable period of time, then the landlord is able to begin eviction proceedings right away.
In New York, rent controlled apartments can often be found as well. Most rent controlled apartments can be found in older buildings with a certain number of units. Provided a property doesn't fall into one of these two categories, then a landlord can do as one pleases.
Because an apartment is unregulated, is doesn't mean that a landlord isn't required to maintain the property in a habitable condition. All landlords are required to ensure that both air and heating units are working properly, that the grounds are cared for, and that lighting is adequate. Additionally, all landlords are responsible for doing whatever is necessary to ensure tenant safety and protection of their belongings.
If you suspect that you've been taken advantage of because you live in an unregulated apartment, a New York City landlord-tenant disputes attorney can provide guidance in your legal matter.
Source: Pocket Sense, "What is an unregulated apartment?," Jerry Shaw, accessed Dec. 22, 2017