“When more and more people are thrown out of work, unemployment results,” Calvin Coolidge once observed. As the U. S. economy crumbles, Coolidge’s silly maxim might appear to be as apt as ever: the number of unemployment insurance claims is rising, and overall joblessness is creeping upward. But in today’s vast and complex labor market, things aren’t always what they seem. More and more people are indeed losing their jobs but not necessarily because the economy appears to be in recession. And old-fashioned unemployment isn’t the inevitable result of job loss. New work, at less pay, often is. 　　Call it new-wave unemployment: structural changes in the economy are overlapping the business downturn, giving joblessness a grim new twist. Small wonder that the U. S. unemployment rate is rising. Now at 5.7 percent, it is widely expected to edge toward 7 percent by the end of next year. But statistics alone can’t fully capture a complex reality. The unemployment rate has been held down by slow growth in the labor force—the number of people working or looking for work—since few people sense attractive job opportunities in a weak economy. In addition, many more people are losing their jobs than are actually ending up unemployed. Faced with hungry mouths to feed, thousands of women, for example, are taking two or more part-time positions or agreeing to shave the hours they work in service-sector jobs. For better and for worse, work in America clearly isn’t what it used to be. Now unemployment isn’t, either. 　　Like sour old wine in new bottles, this downturn blends a little of the old and the new reflecting a decade’s worth of change in the dynamic U. S. economy. Yet, in many respects the decline is following the classic pattern, with new layoffs concentrated among blue-collar workers in the most “cyclical” industries, whose ups and downs track the economy most closely. 　　As the downturn attracts attention on workers’ ill fortunes, some analysts predict that political upheaval may lie ahead. Real wages for the average U. S. worker peaked in 1973 and have been falling almost ever since. As a result, a growing group of downwardly mobile Americans could soon begin pressing policymakers to help produce better-paying jobs. Just how loud the outcry becomes will depend partly on the course of the recession. But in the long run, there’s little doubt that the bleak outlook for jobs and joblessness is “politically, socially and psychologically dynamite”. According to the passage, the unemployment rate has been kept under limits because _____.

“When more and more people are thrown out of work, unemployment results,” Calvin Coolidge once observed. As the U. S. economy crumbles, Coolidge’s silly maxim might appear to be as apt as ever: the number of unemployment insurance claims is rising, and overall joblessness is creeping upward. But in today’s vast and complex labor market, things aren’t always what they seem. More and more people are indeed losing their jobs but not necessarily because the economy appears to be in recession. And old-fashioned unemployment isn’t the inevitable result of job loss. New work, at less pay, often is.
　　Call it new-wave unemployment: structural changes in the economy are overlapping the business downturn, giving joblessness a grim new twist. Small wonder that the U. S. unemployment rate is rising. Now at 5.7 percent, it is widely expected to edge toward 7 percent by the end of next year. But statistics alone can’t fully capture a complex reality. The unemployment rate has been held down by slow growth in the labor force—the number of people working or looking for work—since few people sense attractive job opportunities in a weak economy. In addition, many more people are losing their jobs than are actually ending up unemployed. Faced with hungry mouths to feed, thousands of women, for example, are taking two or more part-time positions or agreeing to shave the hours they work in service-sector jobs. For better and for worse, work in America clearly isn’t what it used to be. Now unemployment isn’t, either.
　　Like sour old wine in new bottles, this downturn blends a little of the old and the new reflecting a decade’s worth of change in the dynamic U. S. economy. Yet, in many respects the decline is following the classic pattern, with new layoffs concentrated among blue-collar workers in the most “cyclical” industries, whose ups and downs track the economy most closely.
　　As the downturn attracts attention on workers’ ill fortunes, some analysts predict that political upheaval may lie ahead. Real wages for the average U. S. worker peaked in 1973 and have been falling almost ever since. As a result, a growing group of downwardly mobile Americans could soon begin pressing policymakers to help produce better-paying jobs. Just how loud the outcry becomes will depend partly on the course of the recession. But in the long run, there’s little doubt that the bleak outlook for jobs and joblessness is “politically, socially and psychologically dynamite”.
According to the passage, the unemployment rate has been kept under limits because _____.