The Randstad employee confidence index fell 1.1 points in May to a reading of 53.2 after falling 1.2 points in April. These consecutive dips follow a four-year high reading of 55.5 in March. The index measures workers’ confidence in their personal employment situation and optimism in the economic environment.

“Despite the slight decrease seen in our latest report, we shouldn’t disregard the fact that our Index is still indicative of positive confidence levels,” said Joanie Ruge, senior vice president and chief employment analyst for Randstad Holding. “Clearly, what we are seeing in our survey, as well as in other broader economic indicators, is caution being exercised from both an employee and employer perspective.”

The index is based on an online survey conducted by Harris Interactive on behalf of Randstad. It surveyed 1,204 employed U.S. adults. The survey took place between May 16 and May 18.