American sociologist David Willer (1937-) devoted himself to building his own epistemological, theoretical, and methodological approach, which he called "elementary theory". In his first book, Scientific Sociology: Theory and Method (1967), he proposed the construction of theoretical sociology based on the application of mathematical models in the development and application of scientific sociological laws. Such scientific laws cannot be constructed by generalizing empirically obtained data. In his book Systematic Empiricism: Critique of a Pseudo-Science (1973), Willer, precisely because of the wide application of empirical generalizations, characterizes sociology as a pseudo-science. He believes that sociology can be a science only if it develops precise theories that can be tested empirically.

Willer presents a detailed elaboration of his approach to sociology in the form of "elementary theory" in his book Networks, Exchanges and Coercion (1981). He starts from simple concepts and by combining them develops more complex concepts, and in the end, he derives a set of logically connected principles and laws. At the micro level, there are systems of normatively controlled social exchange, while at the macro level, there are structures of economic exchange and coercion. To test his theory on specific cases, he uses experimental methods, comparative-historical analysis, institutional analysis, and ethnographic case studies. The actors are guided by strategic rationality, and in their actions, they take into account the expected behaviors of others. The values ​​that these actors have are a reflection of the social structures and relationships within which actors operate.

Willer continues to develop his theoretical approach in his book Theory and Experimental Investigation of Social  Structures (1987). He identifies similarities between the structural conditions that create power differences within social exchange networks, on the one hand, and the conditions that sustain coercive structures, on the other. Differences in power are a consequence of mobility in hierarchies and the process of exclusion from exchange structures. Willer tests his theory and its hypotheses in a series of laboratory experiments. Willer also develops computer software that simulates experiments with which he investigates hypotheses derived from elementary theory. In his book Building Experiments: Testing Social Theory (2007), Willer argues that the development of elementary theory, but also all of scientific sociology in general, depends on the development of complex instruments for the precise testing of theoretical predictions.

Books:

Bell, Richard, Henry Walker, and David Willer. “Power, Influence and Legitimacy in Organizations: Implications of Three Theoretical Research Programs.” Research in the Sociology of Organizations (2000);

Corra, Mamadi and David Willer. “The Gatekeeper.” Sociological Theory (2002);

Willer. Scientific Sociology: Theory and Method (1967);

     -     Systematic Empiricism: Critique of a Pseudoscience (1973);

     -     Networks, Exchange and Coercion (1981);

     -     Theory and the Experimental Investigation of Social Structures (1987);

     -     „Power Relations in Exchange Networks”, in American Sociological Review (1988);

     -     Network Exchange Theory (1999);

     -     Building Experiments: Testing Social Theory (2007).