Reducing the high school dropout rate by half would boost spending and tax revenues in the Tulsa area by millions of dollars every year, according to a new study of the dropout rates in the nation's 50 largest cities. The Alliance for Excellent Education estimates that if Tulsa County and seven surrounding counties had only 2,100 dropouts in the class of 2008 instead of 4,200, those graduates would have earned $18 million more a year, leading to significant growth in jobs, home ownership, levels of spending and investment, and car sales.