`Levels of analysis' problems can involve issues regarding (1) the relative potency of different categories of explanatory factors, (2) the relationship between analyses focusing on different units of analysis or (3) the relationship between assumptions about individual social entities and hypotheses regarding interactions among those entities. An analysis of the manner in which economists have dealt with levels of analysis issues and recent developments in the field of international politics focusing on the relationship between regime types and international conflict can facilitate the integration of research efforts involving different levels of analysis. Advocates of `democratic peace' rely increasingly on an assumption that leaders of states place the highest priority on staying in power. This assumption offers a useful basis for the integration of domestic as well as international or environmental explanatory factors. Since this assumption and theoretical notions based on it imply that different types of states behave differently, however, it can also complicate the analysis of interactions among states. Directed dyadic level analyses, and analyses of more complex aggregates using directed dyads as building blocks, can produce data that are more germane to the evaluation of hypotheses regarding the impact of differences between states than aggregate level analyses that typically tend to obscure `who does what to whom'.
