> Every now and then I look at housing costs vs. rental income to consider buying some investment property. But the numbers never work out, I'd always end up loosing money to rent it out.

'Maybe' in the case of buying a new property now to rent. But it's clearly the case for many or there wouldn't be places to rent.

"Where in CA can I buy a house/apt and rent it out for more than the mortgage+insurance+taxes+maintenance?"

Anecdata for sure, but I know of more than a handful of landlords in SF that charge more rent (and get more rental income) than mortgage+insurance+taxes+maintenance. Moreover, that equation ignores the increase in value of the property. You are confusing cashflow with making money, which are two very different things.

My current landlord just bought our entirely rent-controlled building three years ago. As part of the sale/marketing, gross income from the building was made available at a very granular level. It is certain that our landlord is losing money in terms of income-(mortgage+insurance+taxes+maintenance). However, it is equally certain that the landlord has profited greatly. First you have the fact that the building itself has increased in value by about 20% over the last three years. Accordingly, the landlord has made a profit in the low seven figures. Second, you have the straightline depreciation, which is a massive tax benefit if you have other appreciable income.

renting is profitable if you can rent for more than

interest_on_mortgage+insurance+taxes+maintenance-raise_in_house_valuation no?

If your formula was the one, renting would never make any sense...