The Randstad Employee confidence index fell in November to a reading of 51.7, after a previous two-month climb in confidence. The index measures workers’ confidence in their personal employment situation and optimism in the economic environment.

Employees showed increased uncertainty around the availability of new jobs and in the strength of the economy, according to the index. Despite the decrease in optimism, 59 percent of U.S. workers maintain strong levels of confidence in their employers’ future. Additionally, slightly more workers expressed an increased sense of job security.

“November was a month of ups and downs for the U.S. labor market, but for the most part, our index has remained fairly high given the mixed economic headlines,” said Jim Link, managing director of human resources for Randstad US.

“With the presidential election behind us, economic anxiety still exists around the so-called fiscal cliff, potential sharp tax increases, and the economic outlook overseas. Yet, there are some very positive signs as we move into the last month of the year,” Link said.

The index is based on an online survey conducted by Harris Interactive on behalf of Randstad. It surveyed 1,421 employed U.S. adults. The survey took place between Nov. 12 and Nov. 14.