arXiv subjects

Joel Kariel

Publications and source records attributed to Joel Kariel.

2 recordsLinked to original sources

arXiv2026

Scale Economies and Aggregate Productivity

We develop a theoretical framework to investigate the link between rising scale economies and stagnating productivity. Our model features heterogeneous firms, imperfect competition, and firm selection. We demonstrate that scale economies generated by fixed costs have distinct impacts on aggregate productivity compared to those driven by returns to scale (slope of marginal cost). Using UK data, we estimate long-run increases in both fixed costs and returns to scale. Our model implies that this should increase aggregate productivity through improved firm selection and resource allocation. However, increasing markups can offset the productivity gain. Higher markups cushion low-productivity firms' revenues, allowing them to survive, and constrain firm output, which limits exploitation of scale economies.

econ.GN↗

arXiv2025

Rising Marginal Costs, Rising Prices?

We present empirical evidence on the relationship between demand shocks and price changes, conditional on returns to scale. We find that in industries with decreasing returns to scale, demand increases (which raise costs) correspond to price increases. Whereas, in industries with increasing returns to scale, demand increases (which lower costs) correspond to stable prices. We interpret the results with a theory of imperfect competition and returns to scale. For prices to remain stable following a cost decrease, markups necessarily rise. For prices to increase as cost increases, it is not necessary for markups to change but does not preclude their role. From a macroeconomic perspective, our results imply that inflation dynamics and the effectiveness of monetary policy depend on market structures.

econ.GN↗