The government heavily interferes in the housing industry. Hence, the higher costs. It's the same for everything the government interferes with - such as education and health care.

For examples:

1. there are 57,000 unoccupied apartments in NYC because city regulations on rents make them unprofitable to rent out.

2. the glacial pace of issuing building permits for burned out homes in LA.

3. the sudden influx of many millions of immigrants pushes up the demand for housing, resulting in higher prices