Home prices are in free fall. Unemployment is rising. Consumer confidence is plumbing depths not seen since 1980. When will it all end?

The answer is, probably not until 2010 or later. Barack Obama, take notice.

It’s true that some prognosticators still expect a “V-shaped” recovery in which the economy springs back rapidly from its slump. On this view, any day now it will be morning in America.

But if the experience of the last 20 years is any guide, the prospect for the economy isn’t V-shaped, it’s L-ish: rather than springing back, we’ll have a prolonged period of flat or at best slowly improving performance.

Let’s start with housing.

According to the widely used Case-Shiller index, average U.S. home prices fell 17 percent over the past year. Yet we’re in the process of deflating a huge housing bubble, and housing prices probably still have a long way to fall.