Thanks for the link

The two professors came to this conclusion after reviewing answers to 1,779 survey questions asked between 1981 and 2002 on public policy issues. They broke the responses down by income level, and then determined how often certain income levels and organised interest groups saw their policy preferences enacted.

The 2014 study doesn't seem very convincing or empirical if it amounted to two academics reviewing old popular opinion polls, then deciding themselves if the policies were implemented.

Not that I disagree with the conclusion, I just don't see how this moves the needle.