Such paradoxes are still fun to contemplate; they still appear in some freshman textbooks. Nonetheless, few economists take them seriously these days. There are a number of reasons, but the most important can be stated in two words: Alan Greenspan.
       After all, the simple Keynesian story is one in which interest rates are independent of the level of employment and output. But in reality the Federal Reserve Board actively manages interest rates, pushing them down when it thinks employment is too low and raising them when it thinks the economy is overheating. You may quarrel with the Fed chairman's judgment--you may think that he should keep the economy on a looser rein--but you can hardly dispute his power. Indeed, if you want a simple model for predicting the unemployment rate in the United States over the next few years, here it is: It will be what Greenspan wants it to be, plus or minus a random error reflecting the fact that he is not quite God.

But putting Greenspan (or his successor) into the picture restores much of the classical vision of the macroeconomy. Instead of an invisible hand pushing the economy toward full employment in some unspecified long run, we have the visible hand of the Fed pushing us toward its estimate of the noninflationary unemployment rate over the course of two or three years. To accomplish this, the board must raise or lower interest rates to bring savings and investment at that target unemployment rate in line with each other. And so all the paradoxes of thrift, widow's cruses, and so on become irrelevant. In particular, an increase in the savings rate will translate into higher investment after all, because the Fed will make sure that it does.
       To me, at least, the idea that changes in demand will normally be offset by Fed policy--so that they will, on average, have no effect on employment--seems both simple and entirely reasonable. Yet it is clear that very few people outside the world of academic economics think about things that way. For example, the debate over the North American Free Trade Agreement was conducted almost entirely in terms of supposed job creation or destruction. The obvious (to me) point that the average unemployment rate over the next 10 years will be what the Fed wants it to be, regardless of the U.S.-Mexico trade balance, never made it into the public consciousness. (In fact, when I made that argument at one panel discussion in 1993, a fellow panelist--a NAFTA advocate, as it happens--exploded in rage: "It's remarks like that that make people hate economists!")

Whathas made it into the public consciousness--including, alas, that of many policy intellectuals who imagine themselves well informed--is a sort of caricature Keynesianism, the hallmark of which is an uncritical acceptance of the idea that reduced consumer spending is always a bad thing. In the United States, where inflation and the budget deficit have receded for the time being, vulgar Keynesianism has recently staged an impressive comeback. The paradox of thrift and the widow's cruse are both major themes in William Greider's latest book, which I discussed last month. (Although it is doubtful whether Greider is aware of the source of his ideas--as Keynes wrote, "Practical men, who believe themselves quite exempt from any intellectual influence, are usually the slaves of some defunct economist.") It is perhaps not surprising that the same ideas are echoed by John B. Judis in the New Republic; but when you see the idea that higher savings will actually reduce growth treated seriously in Business Week ("Looking for Growth in All the Wrong Places," Feb. 3), you realize that there is a real cultural phenomenon developing.
       To justify the claim that savings are actually bad for growth (as opposed to the quite different, more reasonable position that they are not as crucial as some would claim), you must convincingly argue that the Fed is impotent--that it cannot, by lowering interest rates, ensure that an increase in desired savings gets translated into higher investment.

It is not enough to argue that interest rates are only one of several influences on investment. That is like saying that my pressure on the gas pedal is only one of many influences on the speed of my car. So what? I am able to adjust that pressure, and so my car's speed is normally determined by how fast I think I can safely drive. Similarly, Greenspan is able to change interest rates freely (the Fed can double the money supply in a day, if it wants to), and so the level of employment is normally determined by how high he thinks it can safely go--end of story.
       No, to make sense of the claim that savings are bad you must argue either that interest rates have no effect on spending (try telling that to the National Association of Homebuilders) or that potential savings are so high compared with investment opportunities that the Fed cannot bring the two in line even at a near-zero interest rate. The latter was a reasonable position during the 1930s, when the rate on Treasury bills was less than one-tenth of 1 percent; it is an arguable claim right now for Japan, where interest rates are about 1 percent. (Actually, I think that the Bank of Japan could still pull that economy out of its funk, and that its passivity is a case of gross malfeasance. That, however, is a subject for another column.) But the bank that holds a mortgage on my house sends me a little notice each month assuring me that the interest rate in America is still quite positive, thank you.
       Anyway, this is a moot point, because the people who insist that savings are bad do not think that the Fed is impotent. On the contrary, they are generally the same people who insist that the disappointing performance of the U.S. economy over the past generation is all the Fed's fault, and that we could grow our way out of our troubles if only Greenspan would let us.