My grandparents lived in rent controlled apartments in NYC that they could not have afforded to stay in
This is selection bias. Suppose the government raised the federal minimum wage to $50/hr. This would cause massive unemployment (and, no doubt, a thriving black market for labor), but some lucky low-income workers would keep their jobs. You could then point to one of those workers and say, "Hey, I know someone who has a high-paying job that wouldn't exist but for the new minimum wage." But this ignores the damage done to everyone else through unemployment and higher prices. And so it goes with your lucky grandparents.
You can avoid these sorts of errors by consistent application of the following rule:
The art of economics consists in looking not merely at the immediate but at the longer effects of any act or policy; it consists in tracing the consequences of that policy not merely for one group but for all groups.
I gave a counter-example to show how ridiculous it is to talk about this through anecdotes. Yes, it's selection bias -- the entire top-rated comment on this thread is full of anecdotes are data arguments. Thanks for the pointers on avoiding this error in the future -- sheesh.
Okay, fine, but the op that he's replying to suffered the same flaw by pointing to cases of politically connected wealthy people in rent-controlled apartments. Where's the proof that rent-control inflicts large systemic damage across all groups? It's certainly not in the topic's article (see my other post).
This is selection bias. Suppose the government raised the federal minimum wage to $50/hr. This would cause massive unemployment (and, no doubt, a thriving black market for labor), but some lucky low-income workers would keep their jobs. You could then point to one of those workers and say, "Hey, I know someone who has a high-paying job that wouldn't exist but for the new minimum wage." But this ignores the damage done to everyone else through unemployment and higher prices. And so it goes with your lucky grandparents.
You can avoid these sorts of errors by consistent application of the following rule:
The art of economics consists in looking not merely at the immediate but at the longer effects of any act or policy; it consists in tracing the consequences of that policy not merely for one group but for all groups.
-- Henry Hazlitt, Economics in One Lesson http://jim.com/econ/contents.html