Abstract
This work puts into close relationship the approach of Analytical Sociology, characterised by a search for explanatory social mechanisms, and the tools of Complexity Science, particularly useful for studying social systems characterised by non-linearity and out of equilibrium dynamics. It starts by presenting arguments for analytical social research, touching on epistemological, theoretical and methodological issues. After having introduced and debated the analytical approach to social theory, it describes a kind of bounded rationality that seems to be consistent with both the methodological individualism implied by the approach and the need for final explanations of social phenomena. The focus then passes onto the choice of an appropriate tool for the analysis of social systems: Agent Based Simulations. In the second half of the work this framework is applied to a social dilemma, voluntary public good provision. The critical point about the provision of public good is connected to the general social dilemma of cooperation: individuals would improve their wealth by making a full contribution to the public good in the case of cooperation with others, but free riding can be widespread and have a strong impact on the system dynamics. Thus the work, having introduced some not very common tools, concentrates on attempts to analyse and simulate the behaviour of subjects in economic experiments about the voluntary provision of public goods, pointing out that the mechanism in such dilemma is mainly the result of conditional cooperation. A case study of a rural community in Italy helps to validate the results and to direct attention to some other key issues, such as the structure of the interactions between the community members. The work ends by presenting a mechanism-based theory of voluntary public good provision that helps in understanding the boundaries of validity of social explanation and in extending it.