ABSTRACT This paper makes a comparative and critical analysis of the main theories of economic growth both exogenous and endogenous, from the Harrod-Domar model to the Romer model, with the aim of establishing the importance of growth models assigned to the policy sustaining economic growth over the long term. The study shows that especially in the latest models, there are no clear economic policy guidelines, or with large doses of prediction, because the theory has played torn between sacrificing the economic justification for the sake of mathematical rigor required by the formalization, and/or sacrificing the theoretical legitimacy in order to offer interpretations of economic processes such as growth.