Much of the language used to describe monetary policy, such as "steering the economy to a soft landing "or" a touch on the brakes" , makes it sound like a precise science. Nothing could be farther from the truth. The link between (52)______ interest rates and inflation is uncertain. And there are long, variable lags after (53)______ policy changes have any effect on the economy. Giving all these disadvantages, central bankers seem to have had much to (54)______ boast about Of late. It is also less than most forecasters had predicted. In late 1994 the panel of economists which The Economist had polled each month (55)______ said that America’s inflation rate would average 3.5% in 1995. In fact, it fell to 2.6% in August, and is expected to average only about 3% for the year a (56)______ whole. In Britain and Japan inflation is running half a percentage point below the rate predicted at the end of last year. This is no flash in the pot; over the (57)______ past couple of years, inflation has been consistently lower than expected in Britain and America. Economists have been particularly surprised by unfavorable inflation fig- (58)______ ures in Britain and the United States, since conventional measures suggest that both economies, and especially America’s, have little productive slack. America’s capacity utilization, for example, hits historically high levels earlier (59)______ this year, and its jobless rate has fallen below most estimation of the natural (60)______ rate of unemployment -- the rate below which inflation has taken off in the past. Why has inflation proved so mild The most thrilling explanation is, fortunately, a little defective. Some economists argue that powerful structural (61)______ changes in the world have upended the old economic models that were based upon the historical link between growth and inflation.