As noted by others here, it discourages maintenance and property improvements to rent control units. The landlord has an incentive to create a terrible living situation to get the tenant to move out.
An enforcement in issue. In NYC the laws are actually aggressively pro-tenant on the issue of deliberate neglect; if you don't keep the basic services working (or keep the building reasonably free of infestations, for example), the tenant can use that to delay any attempted eviction processes (justified or otherwise) quite substantially. The smarter landlords in NYC all know this, and hence generally resort to buy-outs as a tool for vacating tenants. Overt harassment-by-neglect does happen, but is quite rare.
It also reduces tenant mobility.
To some extent, it reduces mobility within the local market (and this effect can be quite significant, in some markets). But in an unregulated environment, a great many of these people simply would not be able to continue renting in the local market, at all. So it's a tradeoff, basically.
Rent control also directly causes Ellis Act evictions, IMO.
A non-sequitur; there's no reason one needs to have something like the Ellis Act in order to have rent control. NYC's market (famously) does not, for example; and profit-driven conversions of the sort you mention are generally illegal, and easily blocked in landlord-tenant court.
In other words, the Ellis Act causes Ellis Act evictions; not "rent control."
"Rent is too high, I know let me pass a law to make high rent illegal".
Rent control is causing a shortage of suitable living areas and property owners are ignoring maintenance costs.
"Well then, let's pass another law!"
Property owners are passing rent controlled properties to their friends and family, or influencing local government regulations to do complicated rezoning laws or even straight up bribing inspectors
"hmmm, well let's just pass more laws then!"
How many times are you willing to try a solution that continues to fail before you give up? It would be funny except in the mean time your belief that a couple "smart people(TM)" passing laws is ruining the lives of the very people you profess to want to help.
EDIT: The fact you believe it is perfectly reasonable for landlords to be held hostage and forced to do 'buy outs' of tenants who refuse to leave an apartment that isn't theirs is all I need to know about your thug mentality.
There's no particular reason to think rent control is causing a shortage in SF. New construction is not under rent control, so it does not harm incentives to create new housing. And given the prices even rent-controlled buildings are selling for, it's clear that people are lining up to be landlords in SF.
Don't forget that new construction in SF totally stopped for a few years after Lehman, and rents actually fell a little.
If rent control were actually causing a shortage, we'd expect that rents would have continued to rise during that time. Instead, the far more likely conclusion, given the data, is that rents are being driven mostly by increases in demand.
It is difficult for the armchair libertarian economists of HN to accept that, while rent control probably puts some upward pressure on rents (in theory, anyway), that effect is likely totally swamped by the demand-side imbalance.
I'm not sure how strong that is - after Lehman the housing market collapsed, wouldn't it follow that 2008 crash had a greater effect on lowering rents as well?
I don't live in SF so I can't speak to that, but in the Boston area it caused rents to go up. No one wants to buy a house when home prices are falling month-over-month. A lot of people looked around and decided they didn't want to get locked in and risk being underwater. A lot no longer qualified for standard mortgages. Many people simply lost their jobs, so home ownership was out of the question. Plus the glut of foreclosures. But people still need a place to live, so the demand for rental units shot up even as home prices and mortgage rates were falling.
An enforcement in issue. In NYC the laws are actually aggressively pro-tenant on the issue of deliberate neglect; if you don't keep the basic services working (or keep the building reasonably free of infestations, for example), the tenant can use that to delay any attempted eviction processes (justified or otherwise) quite substantially. The smarter landlords in NYC all know this, and hence generally resort to buy-outs as a tool for vacating tenants. Overt harassment-by-neglect does happen, but is quite rare.
It also reduces tenant mobility.
To some extent, it reduces mobility within the local market (and this effect can be quite significant, in some markets). But in an unregulated environment, a great many of these people simply would not be able to continue renting in the local market, at all. So it's a tradeoff, basically.
Rent control also directly causes Ellis Act evictions, IMO.
A non-sequitur; there's no reason one needs to have something like the Ellis Act in order to have rent control. NYC's market (famously) does not, for example; and profit-driven conversions of the sort you mention are generally illegal, and easily blocked in landlord-tenant court.
In other words, the Ellis Act causes Ellis Act evictions; not "rent control."