Many economists are sceptical about the economic benefits of hosting the Olympic Games, emphasising that such "mega-events" often have large costs while yielding relatively few tangible benefits in the long run.[75] Conversely hosting (or even bidding for) the Olympics appears to increase the host country's exports, as the host or candidate country sends a signal about trade openness when bidding to host the Games.[76] Moreover, research suggests that hosting the Summer Olympics has a strong positive effect on the philanthropic contributions of corporations headquartered in the host city, which seems to benefit the local nonprofit sector.