WITH unemployment rising and the financial system in shambles, it’s hard not to feel negative about the economy right now. The answer to our problems, however, could well be more negativity. But I’m not talking about attitude. I‘m talking about numbers.

Let’s start with the basics: What is the best way for an economy to escape a recession?

Until recently, most economists relied on monetary policy. Recessions result from an insufficient demand for goods and services  and so, the thinking goes, our central bank can remedy this deficiency by cutting interest rates. Lower interest rates encourage households and businesses to borrow and spend. More spending means more demand for goods and services, which leads to greater employment for workers to meet that demand.

The problem today, it seems, is that the Federal Reserve has done just about as much interest rate cutting as it can. Its target for the federal funds rate is about zero, so it has turned to other tools, such as buying longer-term debt securities, to get the economy going again. But the efficacy of those tools is uncertain, and there are risks associated with them.

In many ways today, the Fed is in uncharted waters.

So why shouldn’t the Fed just keep cutting interest rates? Why not lower the target interest rate to, say, negative 3 percent?