Since the beginning of transition, Eastern European and Central Asian (ECA) countries compete against one another in attracting foreign investors by offering ever more generous incentive packages. Recent empirical research provides though little support for the idea that foreign direct investments (FDI) have a positive effect on local economies. This paper examines then whether FDI benefits are sufficient to justify the kind of policy interventions seen in practice. Analysis focuses on the impact of the increasing presence of multinationals on the economic development of transition economies in ECA through the generation of vertical and horizontal spillovers. Our theoretical model shows that policies which promote FDI are more likely to be justified on welfare grounds if multinationals engage in technology transfer that improves local suppliers' productivity, multinationals' technological advantage over the local competitors is only moderate, and the establishment of foreign affiliates does not lower the local processors' market share. Using data from the Business Environment and Enterprise Performance Surveys (BEEPS), empirical research suggest, however, that foreign investments are more likely to have a positive impact on their local suppliers, and a negative one on their llocal competitors, implying that the second and third conditions are unlikely to hold.