Conventions bring tourism and business dollars to cities. But recently the industry has been lagging.  With numerous cities across the nation building or expanding centers, some experts suggest it may be time to reevaluate these investments. Doug Ducate, president and CEO of the Center for Exhibition Industry Research, feels conventions are always going to be important, but the industry is currently shaky. “We’ve seen nine consecutive quarters of decline… There was roughly a 10 percent...