Planners who move their meetings from city to city should compare labor rates in new destinations so they can estimate costs and manage exhibitor expectations. One tried-and-true resource is Tradeshow Week's annual survey of U.S. and Canadian labor rates.

After spiking as much as 5 percent to 10 percent in years past, the average cost of labor at convention centers has plateaued, according to the 2004 survey. “Most top-tier cities are comparable in price,” says Michael Hughes, associate publisher and director of research services for the Los Angeles-based publication. “It's the work rules that impact price, and they vary.”

When comparing costs, be sure to ask which unions perform what services, and when overtime charges apply.