[1] In social science research, at the macro level, the most commonly referenced unit of analysis, considered to be a society is the state (polity) (i.e. country).
Together, the unit of observation and the level of analysis define the population of a research enterprise.
[4] Dependency theory and world-systems analysis challenged the treatment of countries as societies or units of analysis and the assumption that each country develops separately through stages from agrarian to industrial, from authoritarian to democratic, from backwards to advanced, by raising historical evidence.
The development of an uneven division of labor (world-economy) shows factors of causality that account for changes within countries indicating that countries are part of a larger society or historical social system with systemic patterns that account for global inequality.
[citation needed] The literature of international relations provides a good example of units of analysis system.[how?]