MarketWatch shares a study released by RealtyTrac that sums up how much profit the rental market is making in certain areas of the country.
Of the 10 counties with the worst rental returns, five were in California and three in New York. This is because markets like New York City and San Francisco tend to have high home prices, which makes it hard to get enough money in rent to cover the mortgage. New York City and San Francisco each tended to have annual gross rental yields below 4 percent.