This inquiry emphasizes the importance of the meso-level for social analysis. We consider the micro- meso- and macro-levels of social analysis and relate these to the institutionalist approaches for sociology and economics. We cite numerous studies that understand the “mesolevel” as a space of rules’ formation in which micro-level actors interact. Their interacting then generates macrostructures taking on their own distinct characteristics, and are thus not reducible to the properties of their constituent elements. For the micro-level of social analysis a principle of methodological individualism is relevant, where as holism principle is significant for the macrolevel. In addition two mentioned principles we promote a new perspective of social analysis that we define as “methodological/ institutionalism”. Its content, as well as applications are considered in the paper.