How Does the Job of a Baseball Manager Compare to President Obama?

Baseball economists have tried to measure how much impact a baseball manager has on the outcome of games. They found that while some might be slightly better than the others, it's not a big difference between one manager at the next. As they move from team to team, players tend to perform about as well as they always have. Some managers do seem to have a little bit better performance than others, but it's not statistically different from any other manager.