Nowhere has there been so much hand-wringing over a lack of "affordable housing," as among politicians and others in coastal California. And nobody has done more to make housing unaffordable than those same politicians and their supporters.

A recent survey showed that the average monthly rent for a one-bedroom apartment in San Francisco was just over $3,500. Some people are paying $1,800 a month just to rent a bunk bed in a San Francisco apartment.

It is not just in San Francisco that putting a roof over your head can take a big chunk out of your pay check. The whole Bay Area is like that. Thirty miles away, Palo Alto home prices are similarly unbelievable.

One house in Palo Alto, built more than 70 years ago, and just over one thousand square feet in size, was offered for sale at $1.5 million. And most asking prices are bid up further in such places.

Another city in the Bay Area with astronomical housing prices, San Mateo, recently held a public meeting and appointed a task force to look into the issue of "affordable housing."

Public meetings, task forces and political hand-wringing about a need for "affordable housing" occur all up and down the San Francisco peninsula, because this is supposed to be such a "complex" issue.

Someone once told President Ronald Reagan that a solution to some controversial issue was "complex." President Reagan replied that the issue was in fact simple, "but it is not easy."

Is the solution to unaffordable housing prices in parts of California simple? Yes. It is as simple as supply and demand. What gets complicated is evading the obvious, because it is politically painful.

One of the first things taught in an introductory economics course is supply and demand. When a growing population creates a growing demand for housing, and the government blocks housing from being built, the price of existing housing goes up.

This is not a breakthrough on the frontiers of knowledge. Economists have understood supply and demand for centuries — and so have many other people who never studied economics.

Housing prices in San Francisco, and in many other communities for miles around, were once no higher than in the rest of the United States.

But, beginning in the 1970s, housing prices in these communities skyrocketed to three or four times the national average.