The article shows that when it comes to funding transportation projects, legislators tend to focus on their own districts to get more benefits while trying to keep overall costs down. This can lead to inefficient spending on public goods. By analyzing Congressional votes from 1998, the researchers found that politicians are more likely to support projects that benefit their own districts and less likely to support projects that come with higher tax burdens for everyone. This means that some districts end up getting more than they should, leading to wasted resources.