Clinton administration in the U.S. Leading Polish sociologist, Zygmunt Bauman, wrote extensively on the concepts of modernity and postmodernity, particularly with regard to the Holocaust and consumerism as historical phenomena. While Pierre Bourdieu gained significant critical acclaim for his continued work on cultural capital, certain French sociologists, particularly Jean Baudrillard and Michel Maffesoli, were criticised for perceived obfuscation and relativism. Functionalist systems theorists such as Niklas Luhmann remained dominant forces in sociology up to the end of the century. In 1994, Robert K. Merton won the National Medal of Science for his contributions to the sociology of science. The positivist tradition is popular to this day, particularly in the United States. The discipline's two most widely cited American journals, the American Journal of Sociology and the American Sociological Review, primarily publish research in the positivist tradition, with ASR exhibiting greater diversity (the British Journal of Sociology, on the other hand, publishes primarily non-positivist articles). The twentieth century saw improvements to the quantitative methodologies employed in sociology. The development of longitudinal studies that follow the same population over the course of years or decades enabled researchers to study long-term phenomena and increased the researchers' ability to infer causality. 21st century sociology The increase in the size of data sets produced by the new survey methods was followed by the invention of new statistical techniques for analyzing this data. Analysis of this sort is usually performed with statistical software packages such as R, SAS, Stata, or SPSS. Social network analysis is an example of a new paradigm in the positivist tradition. The influence of social network analysis is pervasive in many sociological sub fields such as economic sociology (see the work of J. Clyde Mitchell, Harrison White, or Mark Granovetter, for example), organizational behavior, historical sociology, political sociology, or the sociology of education. There is also a minor revival of a more independent, empirical sociology in the spirit of C. Wright Mills, and his studies of the Power Elite in the United States of America, according to Stanley Aronowitz. Critical realism is a philosophical approach to understanding science developed by Roy Bhaskar (1944–2014). It combines a general philosophy of science (transcendental realism) with a philosophy of social science (critical naturalism). It specifically opposes forms of empiricism and positivism by viewing science as concerned with identifying causal mechanisms. Also, in the context of social science it argues that scientific investigation can lead directly