propensity to endorse a candidate, particularly an incumbent. In the 1940s and the 1950s, there was a clear advantage to Republican candidates, that advantage continuously eroded in subsequent decades to the extent that in the 1990s the authors found a slight Democratic lead in the average endorsement choice. Riccardo Puglisi of the Massachusetts Institute of Technology looked at the editorial choices of The New York Times from 1946 to 1997. He found that the Times displays Democratic partisanship, with some watchdog aspects. During presidential campaigns the Times systematically gives more coverage to Democratic topics of civil rights, health care, labor and social welfare but only when the incumbent president is a Republican. Those topics are classified as Democratic ones because Gallup polls show that average US citizens think that Democratic candidates would be better at handling problems related to them. According to Puglisi, the Times since 1960 displays a more symmetric type of watchdog behavior just because during presidential campaigns, it also gives more coverage to the typically-Republican issue of defense when the incumbent president is a Democrat but less so when the incumbent is a Republican. John Lott and Kevin Hassett of the conservative thinktank American Enterprise Institute studied the coverage of economic news by looking at a panel of 389 US newspapers from 1991 to 2004 and a subsample of the two ten newspapers and the Associated Press from 1985 to 2004. For each release of official data about a set of economic indicators, the authors analyzed how newspapers decide to report on them, as reflected by the tone of the related headlines. The idea was to check whether newspapers display partisan bias, by giving more positive or negative coverage to the same economic figure, as a function of the political affiliation of the incumbent president. Controlling for the economic data being released, the authors find that there are 9.6–14.7% fewer positive stories when the incumbent president is a Republican. According to Fairness and Accuracy in Reporting, a liberal watchdog group, the Democratic candidate John Edwards was falsely maligned and was not given coverage commensurate with his standing in presidential campaign coverage because his message questioned corporate power. A 2000 meta-analysis of research in 59 quantitative studies of media bias in American presidential campaigns from 1948 through 1996 found that media bias tends to cancel out, leaving little or no net bias. The authors concluded, "It is clear