In our study, we have investigated how social cohesion affects economic development and investment attracting in Bosnia and Herzegovina. We explain how this influence manifests itself. For the needs of research, quantitative indicators of economic success and social cohesion have been determined and analyzed. Qualitative methods were also used. Semi-structured interviews were conducted with representatives of different organizations and institutions. Four municipalities in Bosnia and Herzegovina were selected and presented as case studies, namely the Municipality of Zavidovići, Bosanska Krupa Municipality, Prijedor Municipality and the Municipality of Tešanj. Qualitative findings have shown that (1) social cohesion is an important prerequisite for economic development, and by working on its increase, better conditions can be achieved and thus increase the chances for new investments. Secondly, (2) low social cohesion allows high-level politics to affect the slowdown in economic development in BiH, and that (3) the ethnic composition of a community does not represent an obstacle to foreign investors, nor an obstacle to the co-operation of municipalities of a different ethnic composition. Quantitative findings show that (4) most variations in economic success are in correlation with the structural factors that municipalities can not influence (the current development of municipalities, their size, the capital status, the entity in which they are located), and that (5) understanding of economic results is important and certain elements of social cohesion. Of particular significance is the ethnic structure of the municipality (ethnic fractionation and polarization of the population), and how effective is the work of the institutions in that municipality. Based on these findings, a model for the development of municipalities has been formulated, that is, the "openness philosophy" that municipalities need to follow to ensure economic development. What distinguishes municipalities is to what extent and how authentically this philosophy of openness is pursued.