White roofs do help

It seems so obvious that I'm surprised that a law has not been passed forcing all flat roof buildings to be painted white. But aside from that, I con't understand why people don't paint their house's roof white just to take down the heat in the summer. Here is CICESE the roofs were all white, but this last year they repainted all of them red.. which makes no sense and was a very uninformed move.

Well, there is not good data from simulations stating the obvious.. white roofs are a good idea; Computer modeling indicates white roofs may be a good idea.