That is a recent paper by Lee Epstein and Eric A. Posner, and here is the abstract:
A statistical analysis of voting by Supreme Court justices from 1937-2014 provides evidence of a “loyalty effect” — justices more frequently vote for the government when the president who appointed them is in office than when subsequent presidents lead the government. This effect exists even when subsequent presidents are of the same party as the justices in question. However, the loyalty effect is much stronger for Democratic justices than for Republican justices. This may be because Republican presidents are more ideologically committed than Democratic justices are, leaving less room for demonstrations of loyalty.
You can read it here.