The Housing Boom and Bust

Sowell's arguments are more complex than this, but if you want the general idea of the book, here it is:

Housing became unaffordable in many cities due to laws that restricted land use and sale.

Fewer people could afford the more expensive homes so government, to promote higher home ownership and end ostensibly racist lending practices, imposed regulations that encouraged, and in some cases, forced lenders to offer loans to under-qualified applicants.

People who couldn't otherwise afford to buy homes took advantage of the newly available financing and bought houses. The large influx of borrowers who were previously priced out of the market led to a housing boom. After a short period of time many of these new homeowners found they couldn't pay their mortgages, leading to large numbers of foreclosures and the subsequent housing bust.

Sowell would place probably 75% of the blame on government and politicians and divide the remaining 25% on lenders (Wall Street etc.) and borrowers.

You may disagree with some or all of that summary, but before you write the book and his ideas off completely, it's worth your time to read it. It's short and easy to digest and Sowell is a master of presenting ideas clearly and logically.