Why global stratification appears to be more of an economic system than a social system?

It is likely that the most common way of looking at different societies comes down to economics is because it is the major determining feature. The economic system has an impact on social systems. The sociologist Lenski looked at the sociocultural evolution of societies, hunter gathering tribes had little surplus of food therefore were small egalitarian kinship groups. Pastural and horticultural societies did have an excess of food, therefore they were larger and there was a hierarchical structure. Western societies have a capitalist economic system and that defines their social structure, political structure and the way goods and services are produced.