Chase-Dunn is the author, co-author, editor, or co-editor of over a dozen books, including most notably Global Formation: Structures of The World-Economy, a major theoretical synthesis and restatement of the world-systems approach to the study of social change.
In a nut shell, Chase Dunn took issue with modernization theory which argued that poorer nations in the world economy were primitive becaasue they didn’t have enough contact and trade with more advanced nations. The reasoning went something like this: more contact with the more advanced nations would facilitate a better chance to develop themselves (nations).
Chase Dunn asserted that the contact and unfair trade is exactly what kept these less developed nations in a state of dependency on the more advanced nation(s). If I remember correctly, data was taken from WW2 when the US had to distance itself from some of the peripheral nations while they concentrated their resources to battle the Axis countries. Thus, the nations the US “ignored” during this time frame whould have become more impoverished since they lacked contact with the more advanced nations. However, instead of becoming more impoverished, they in fact became LESS impoversihed (since their resources stayed in their own country).
Chase Dunn aligned with Dependency Theory. The theory arose as a reaction to modernization theory, an earlier theory of development which held that all societies progress through similar stages of development, that today’s underdeveloped areas are thus in a similar situation to that of today’s developed areas at some time in the past, and that, therefore, the task of helping the underdeveloped areas out of poverty is to accelerate them along this supposed common path of development, by various means such as investment, technology transfers, and closer integration into the world market. Dependency theory rejected this view, arguing that underdeveloped countries are not merely primitive versions of developed countries, but have unique features and structures of their own; and, importantly, are in the situation of being the weaker members in a world market economy.