The U.S. unemployment rate dropped 0.1 percentage point to 7.3% in August and a broader measure of unemployment fell to 13.7% from 14%, but the declines came from the wrong reasons.

The drop in the main unemployment rate was driven almost totally by negative factors. The number of people employed fell by about 115,000. The only reason the rate declined is that the overall labor force dropped by a larger 312,000, a possible sign of discouraged long-term jobless dropping out.

The labor force participation rate, which is the percent of the population either working or looking to work, took a tumble to 63.2% — its lowest level since 1978.