Give divided government a chance.

For those of you with a partisan bent, I have some bad news. Our federal government may work better (well, less badly) when at least one house of Congress is controlled by the opposing party. Divided government is, curiously, less divisive. It's also cheaper. The basic reason for this is simple: When one party proposes drastic or foolish measures, the other party can obstruct them. The United States prospers most when excesses are curbed, and, if the numbers from the past 50 years are any indication, divided government is what curbs them.

Let's look at some statistics. From the dawn of the Cold War until today, we've had only two periods of what could be called fiscal restraint: The last six years of the Eisenhower administration, and the last six years of the Clinton administration, both intervals in which the opposition controlled Congress. Under Clinton, the average annual increase in spending was at about one percent, while, under Ike, it was negative. By contrast, our unified governments have gone on fiscal benders. Harry Truman, with the help of a Democratic Congress, sent the money flying, with spending increases of as high as 10 percent a year. Lyndon Johnson was almost as profligate. And today, unfortunately, George W. Bush, with a GOP majority, is the heir to their legacies. To put this in plain numbers, government spending has increased an average of only 1.73 percent annually during periods of divided government. This number more than triples, to 5.26 percent, for periods of unified government. (See accompanying table.) That's a hefty premium to pay for a bit of unity.

Equally striking is that these spending increases have generally found the same recipient: the Pentagon. It's not that unified governments love to purchase bombers, but, rather, that they tend to draw us into war. This may sound improbable at first, but consider this: In 200 years of U.S. history, every one of our conflicts involving more than a week of ground combat has been initiated by a unified government. Each of the four major American wars during the 20th century, for example--World War I, World War II, the Korean War, and the Vietnam War--was initiated by a Democratic president with the support of a Democratic Congress. The current war in Iraq, initiated by a Republican president and backed by a Republican Congress, is consistent with this pattern. It also stands as the only use of military force involving more than a week of ground combat that has been initiated by a Republican president in over a century. Divided government appears to be an important constraint on American participation in war. Needless to say, this reduces outlays in both blood and treasure.

There's one more advantage to tension between our governmental branches: Major reform is more likely to last. Since passing any measure in divided government requires bipartisan support, a shift in majorities is less likely to bring on serious changes or adulterations. The Reagan tax laws of 1981 and 1986, for example, were both approved by a House of Representatives controlled by Democrats and have largely survived. The welfare reform of 1996 was approved by Clinton and a Republican Congress and also endures. By contrast, any efforts during the past several years to reform the federal tax code, Medicare, or Social Security have faltered, and any changes forced through by the GOP would almost certainly be undone as soon as Democrats returned to power. Reforms of real magnitude will almost certainly depend on preventing immoderation and securing bipartisan support, and little of that seems likely in a GOP-only government.

American voters, in their unarticulated collective wisdom, seem to grasp the benefits of divided government, and that's how they've voted for most of the past 50 years. To be sure, divided government is not the stuff of which political legends are made, but, in real life, most of us would take good legislation over good legends. As a life-long Republican and occasional federal official, I must acknowledge a hard truth: I don't much care how a divided government is next realized. And, in 2006, there's only one way that's going to happen.

William A. Niskanen is chairman of the Cato Institute and was a former member and acting chairman of President Reagan's Council of Economic Advisers.