By virtually every indicator, 2007 was a dismal year for American workers. Job growth slowed, unemployment jumped and wages lost what little ground they had gained against inflation since 2003. There is one sliver of good news: the percentage of American workers who belong to a union rose for the first time in three decades.

The Labor Department reported that the number of workers belonging to a union grew by 311,000 to 15.7 million. That means union members increased from 12 percent of the American work force in 2006 to 12.1 percent last year. In the private sector, unions’ share of workers inched ahead from 7.4 percent to 7.46 percent. While the rebound is tiny, and might yet prove to be a statistical mirage, it is the first recorded increase in organized labor’s ranks since the 1970s, when almost one in four workers belonged to a union.

There is little doubt that American workers need unions. Wages today are almost 10 percent lower than they were in 1973, after accounting for inflation. The share of national income devoted to workers’ wages and benefits is at its lowest since the late-1960s, while the share going to profits has surged. The decline in unionization has been a big part of the reason that workers have lost so much ground.

The future of organized labor is not cause for great optimism. Employers have become more aggressive about keeping unions out. Competitive pressures from globalization, deregulation and technological change have resulted in the loss of many union jobs.