Specifically, rent control laws that prevent you from raising the rent more then X% per year and laws that give someone automatic month to month terms after the lease expires..
This is because right now rental rates are artificially depressed. The landlord might have built their financial model on normal market rents. If someone can lock in a way under market rate due to the pandemic and then keep that rate after the pandemic, then the tenant is taking advantage of the market based pricing when it goes down but disavowing the validity of market based pricing when it goes up.
If rent control exemptions were create that allowed the landlord to raise the rent to what it was prior to the pandemic once this is over, then that would be fine. But as it stands, it doesn't seem fair to force the landlords to rent at under market rates (traditional market, i mean) and then also force that rate to be locked in for the future.
A bit off topic, but are US rental contracts for fixed periods? In Europe I'm used to a "valid until further notice" model, with possibility to break the lease with a given notice period (1-3 months) and a chance of yearly rent increases. Very much similar to employment contracts with notice periods and yearly raises.
Many rental contracts have an early termination clause of some sorts. Generally, they charge you an “early termination fee” that’ll come out of your security deposit.
However, the laws also have “breach of contract” provisions: if your landlord is not keeping up the property (such as ignoring requested work orders), you have the right to leave at any time (before your term ends) and get your security deposit back. You may have to go to court over it, but you are offered that protection. It does go two ways though: if you are trashing the place, they can kick you out right away and keep your deposit.
For example, if you signed a 1 year lease, you are required to pay monthly for that entire year or face still penalties. But once you reach the end of your 1 year lease, your rental goes month-to-month. That implies that the rental rate stays the same (unless sufficient notice is given by the landlord, generally 30 or 60 days prior to the end of the 1 year lease). Furthermore, if you want to vacate, you have to provide a certain amount of notice (generally 30 days).
The key difference is whether rent control is in play there. In my Santa Monica apartment it was in play and the rent could only raise once per year and there was a maximum percentage increase allowable per year.
In Washington DC the vast majority of apartments are not under rent control. Consequently, the apartment legally has to default to month-to-month, but it doesn't have to stay the same rate. Generally what that means is that the landlord, 60 days before the end of the 1 year lease, will provide the tenant a new rate sheet with a monthly price is they want a 1-month lease, a different monthly price for a 6-month lease, and a different monthly price for another year lease. The 1-month lease price is generally MUCH MUCH higher than the new 1-year lease. That incentivizes the tenant to sign a longer term agreement and provide the landlord certainty of occupancy.
Another common model is an initial 1 year term that then converts to month-to-month.
Generally speaking, turnover higher than 1/year is incredibly costly for the landlord, so 1 year leases are the norm. Longer periods are too onerous on renters.
In commercial real-estate, though, longer periods are more common (5 and 10 years are not unheard of).