This simple point is shown nicely in a graph in Catherine Rampell's Economix blogpost. The point is simple. Restaurants always want to hire people at low pay and with few benefits. In a weak labor market they can. When we have periods of low unemployment, like the late 1990s and 2005-2007, workers have better options.

Site Maintenance

"The CEPR website currently takes longer to load than usual. We hope to have this and other issues addressed shortly. While this much needed site maintenance is taking place, our content is still available so please continue to slooowwwly surf the pages of our site. Thank you for your patience."