Advocates in favor of hosting mega-events such as the Olympic Summer Games constantly pronounce substantial pecuniary and non-monetary returns that justify the large amounts of public and private investments. A growing body of research tried to identify possible (positive) effects for host cities in terms of spending, employment, and wages but fails to explicitly support that notion. We argue that positive (or negative) effects on a city’s development hinge on a whole set of both tangible and intangible determinants that must jointly be addressed in order to draw reliable conclusions. The logic of compensating differentials implies that any (perceived) increase in a city’s attractiveness, no matter what origin, directly transfers into increasing utility and subsequent migration in order to restore spatial equilibrium. For the first time, we track population growth of all cities hosting the Olympic Sumer Games from 1850 to 2000, in order to identify possible aggregated benefits. Applying simple difference-in-difference specifications with either the ten biggest cities of the host countries or the unsuccessful candidate cities serving as the control group, our results strongly indicate decreasing relative growth rates of host cities after hosting the Olympics. Surprisingly, this points towards general negative aggregated effects of large investments and marketing.