Brazil spent about $3 billion building 12 new or heavily refurbished stadiums for last year's World Cup. Officials promised these taxpayer-funded venues would continue to generate revenue for years, hosting concerts, pro soccer games, and other events.

But as Lourdes Garcia-Navarro at NPR reports, most stadiums are failing to generate much revenue at all. The most expensive one, in Brasilia, is most regularly used as a site for a municipal bus parking lot.

One big problem is that several of the stadiums — including Brasilia's 72,000-seat, $900 million venue — were built in cities where there are only minor league pro teams that don't draw large crowds. This was done so World Cup games could be spread across the entire country, instead of just the southeast, where most of the top pro teams play. It's as if we built gleaming new stadiums in Montana and Alaska for hosting a World Cup in the US.

In Brazil, this plan has left some pretty useless, expensive facilities scattered across the country, because these minor local teams don't sell enough tickets to make playing in the fancy (and expensive-to-maintain) stadiums worthwhile. The rainforest city of Manaus, for instance, is home to a $600 million stadium that was used for exactly four World Cup games. The pro team there currently plays in much smaller training centers, because it'd lose money if it tried to rent out the big stadium.

Many cities have been selling the stadiums to private companies that try to squeeze a bit of revenue out of them, but it's not easy. In Natal, the NPR story reports, a company bought the stadium, but has made little money renting it out for children's birthday parties and weddings, and the facility is now for sale once again.

What makes all this even more infuriating is that in many of these cities, hundreds of thousands of people were displaced from neighborhoods that were torn down to make way for these stadiums. And even though the World Cup was partly billed as a way to upgrade Brazil's overall infrastructure, several of the big projects — such as light-rail systems in São Paulo, Cuiaba, and Fortaleza — still aren't close to being finished.

Of course, the most insane part about all this is that for Brazil, the World Cup was just a prelude to an even bigger waste of public money on sports: the 2016 Summer Olympics in Rio de Janeiro. Though a stadium renovated for the World Cup will be reused for the games, the country will still spend a projected $13.2 billion on other facilities and infrastructure, a number that's likely to continue climbing as the games approach.

There are economists who study the potential economic impact of these events on the cities that host them, and their findings are unequivocal: they don't pay. As Victor Matheson, an economist at College of the Holy Cross, told my colleague Brad Plumer, "My basic takeaway for any city considering a bid for the Olympics is to run away like crazy."