As the Summer Olympics are growing with larger media coverage and sponsorship, host cities have started to attach great importance to the tourism and other likely economic effects that occur by staging such a special event. As a result, a number of studies have been conducted to consider the various economic implications on the hosts. This paper examines and evaluates methods and assumptions used by the economic studies. It also compares ex-ante models and forecasts with the ex-post approach. The aim is to improve the information available to policy makers and potential future hosts of Summer Olympics and other mega-events. Copyright © 2003 John Wiley & Sons, Ltd.