The United States economy continues its amazing performance. It has just marked the longest economic expansion in the country's history, growing for a record 107 consecutive months. The unemployment rolls are shrinking and inflation is under control. Whatever the explanation -- and there is no good one, yet -- the U.S. economy is defying expectations and blazing a trail that other countries can only dream about. Fortunately, other countries are sharing in the wealth being created, as the U.S. acts as an engine for global growth. If conditions suddenly reverse, however, the dream could become a global nightmare.

Eight years of expansion have created 20 million jobs and pushed down unemployment levels to 4 percent, a 30-year low. In January, consumer prices climbed a mere 0.2 percent, import prices increased half that amount and wholesale prices were unchanged. Productivity surged 3.25 percent last year. That is even better than the 2.9 percent annual increase that has been recorded since 1995, a figure that is more than twice the average annual increases of the two previous decades. Growth has swelled the federal government's coffers, producing budget surpluses and allowing politicians to promise to eliminate the $3.6 trillion national debt within 15 years.

The administration of President Bill Clinton anticipates that growth will slow slightly, to 2.9 percent in 2000. Economists have been forecasting a slow-down for three years, but the pace has yet to falter. There is reason to think that it might happen this time, however.