Until the 1950s, use of the term "populism" remained restricted largely to historians studying the People's Party, but in 1954 the U.S. sociologist Edward Shils published an article proposing "populism" as a term to describe anti-elite trends in U.S. society more broadly. Following on from Shils' article, during the 1960s the term "populism" became increasingly popular among sociologists and other academics in the social sciences. In 1967 a Conference on Populism was held at the London School of Economics, the participants of which failed to agree on a clear, single definition. As a result of this scholarly interest, an academic field known as "populism studies" emerged. Interest in the subject grew rapidly: between 1950 and 1960 about 160 publications on populism appeared, while between 1990 and 2000 that number was over 1500. From 2000–2015, about 95 papers and books including the term "populism" were catalogued each year by Web of Science. In 2016, it grew to 266; in 2017, it was 488, and in 2018, it was 615. Taggart argued that this academic interest was not consistent but appeared in "bursts" of research that reflected the political conditions of the time.