Economists Arvind Subramanian, Justin Sandefur, and Dev Patel, known as SS&P, published an essay that challenges the notion of economic convergence, a core tenet of economic theory. Their initial finding suggested poor countries were catching up to rich ones. This was celebrated as evidence of globalization's success. However, they've now reversed course, stating convergence has ended.

This shift is a mea culpa, as the initial findings were a big deal. The Solow-Swan growth model predicts that poor countries should grow faster. In the late 2010s, SS&P announced that this was finally happening, but now, only a few years later, they've retracted that statement. The implications are significant for understanding global economic development and related strategies.

SS&P's initial optimism was based on the idea that globalization and the removal of obstacles were enabling catch-up growth. The recent retraction highlights the complexities of economic development and the challenges in predicting long-term trends. Their work underlines the importance of constantly reevaluating economic models. What happens next is a good question.

Robert Solow's 1956 paper established the framework. Analyzing data, economists initially found convergence didn't exist. Now, the new data reveals that the gap between rich and poor countries is widening again. This reversal indicates the need to reassess the factors driving global economic disparities and the effectiveness of development policies.