The U.S. prime-age labor force participation rate jumped to a 23-year high

​The share of Americans between the ages of 25 and 54 who have a job or are actively looking for one surged in July to a 23-year high. That added a bright spot to what had looked like a more negative monthly jobs report.

Bloomberg reported that the prime-age labor force participation rate rose to 84 percent, the highest level since 2001 and close to the all-time high set in the late 1990s. At the same time, the overall unemployment rate rose to 4.3 percent, raising concerns that the labor market is weakening.

The rise in the unemployment rate is partly explained by higher Labour force participation. That could indicate that more people are rejoining the labor force because they are optimistic about finding work, boosting the number of unemployed workers.

Stephen Stanley, chief economist at brokerage Santander Capital Markets US, said in the report: "Typically in a recession, the labor force shrinks because discouraged workers give up looking for work, and employment shrinks at a faster rate... That is not what we are seeing now."

The biggest increase in Labour force participation was among prime-age men, whose participation rate rose to 90 per cent, the highest since 2009. The labor force participation rate for prime-age women rose to 78.1 percent, matching the record set earlier this year.