Gravity and Entropy in Economics: two complementary concepts for economy of development, inequality and policy tradeoffs

This paper proposes a metaphorical usage of the gravity model and entropy-based approaches in economics and social sciences. Rather than treating gravity and entropy as direct transpositions of physical laws, this paper interprets them as complementary metaphors capturing two fundamental and persistent forces shaping economic systems. On the one hand, gravity represents forces of attraction, concentration, and accumulation. It permits therefore to analyze processes such as agglomeration, capital accumulation, and the spatial clustering of economic activity. On the other hand, entropy represents statistical dispersion, redistribution, and diversification that contributes to quantizing macroscopic effects arising from the behavior of units. Drawing on insights from economic geography, growth theory, and complexity economics —particularly the centripetal and centrifugal forces highlighted by Krugman— the paper argues that economic development can be represented as a dynamic tension between these opposing properties. Accumulation enhances productivity and innovation through scale effects and knowledge concentration, while redistribution and diffusion mitigate fragility, reduce inequality, and improve allocative efficiency. By framing gravity and entropy as metaphorical lenses, this paper offers a physical point of view to understand development, inequality, and policy trade-offs with fields or forces of attraction and statistical emergentism.