Mathiness in the Theory of Economic Growth

Politics does not lead to a broadly shared consensus. It has to yield a decision, whether or not a consensus prevails. As a result, political institutions create incentives for participants to exaggerate disagreements between factions. Words that are evocative and ambiguous better serve factional interests than words that are analytical and precise. Science is a process that does lead to a broadly shared consensus. It is arguably the only social process that does. Consensus forms around theoretical and empirical statements that are true. Tight links between words from natural language and symbols from the formal language of mathematics encourage the use of words that are analytical and precise. For the last two decades, growth theory has made no scientific progress toward a consensus. The challenge is how to model the scale effects introduced by nonrival ideas. Mobile telephony is the update to the pin factory, the demonstration that scale effects are too important to ignore. To accommodate them, many growth theorists have embraced monopolistic competition, but an influential group of traditionalists continues to support price taking with external increasing returns. The question posed here is why the methods of science have failed to resolve the disagreement between these two groups. Economists usually stick to science. Robert Solow (1956) was engaged in science when he developed his mathematical theory of growth. But they can get drawn into academic politics. Joan Robinson (1956) was engaged in academic Mathiness in the Theory of Economic Growth