“Any country with an expanding middle class and a rising number of unemployed graduates is in for trouble,” said Gerard A. Postiglione, the director of the Wah Ching Center of Research on Education in China at Hong Kong University.

A national survey released last winter found that in the age bracket of 21- to 25-year-olds, 16 percent of the men and women with college degrees were unemployed.

But only 4 percent of those with an elementary school education were unemployed, a sign of voracious corporate demand persisting for blue-collar workers. Wages for workers who have come in from rural areas to urban factories have surged 70 percent in the last four years; wages for young people in white-collar sectors have barely stayed steady or have even declined.

Economists have long estimated that the Chinese economy needs to grow 7 or 8 percent annually to avoid large-scale unemployment. But that rule of thumb has become less reliable in recent years as the labor market has split.

Relatively slow growth is still creating enough jobs to provide full employment for the country’s blue-collar workers. But much faster growth may be needed to create white-collar jobs for the graduates pouring out of universities.

The International Monetary Fund predicts the Chinese economy will grow 7.75 percent this year — slower than the growth of 10 to 14 percent before 2008, but still a much faster pace than in the West. The main problem for China lies in the sheer growth in graduates; the United States produces three million graduates a year, while China has increased its annual number of graduates by more than five million in a single decade.