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Essays in Applied Microeconomics



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Lyu, Yuan 


This thesis comprises three independent papers on applied microeconomics. The first chapter studies the impact of primary care provider mergers on quality in England. The second chapter investigates the effect of price dispersion on consumer search behavior, drawing evidence from the retail gasoline market in Greece. The final chapter builds on the second, studying the asymmetric price adjustment and the impact of market competition on the asymmetric price adjustment. The details of the three papers are summarized below:

The Effects of General Practice Mergers on Quality in England

The primary care market has witnessed a growing trend of provider consolidation through mergers and acquisitions, yet the implications of this concentration remain uncertain. This study addresses this gap by providing the first empirical evidence on the effects of provider mergers on quality using evidence from the English primary care market. By analyzing all provider mergers from 2014 to 2018, I find predominantly negative effects of mergers on quality. Clinical quality does not change at best, and patient satisfaction decreases dramatically. Notably, the impact on quality varies based on the size of the general practices involved. Mergers between large general practices show a detrimental impact on quality, while mergers between small general practices may yield quality benefits. Additionally, there is no difference in the quality impact between mergers involving parties in the same geographical market and those in different markets. An exploration of the mechanism reveals that mismanagement, rather than changes in market concentration, drives the observed decline in quality following mergers.

The Effect of Competition and Price Dispersion on Search Behavior

We investigate the impact of price dispersion on consumer search behavior, while credibly controlling for market structure. Using the retail gasoline market on isolated, oligopolistic markets, as defined by small Greek islands, we exploit an excise duty tax increase policy as a plausibly exogenous shock to price dispersion. We directly measure consumer search using the number of user visits to a price information platform and mobile application. We find that the tax shock increases price dispersion and that in turn causes a short term increase in consumer search. The effect of price dispersion on consumer search remains regardless of market competition level.

Asymmetric Pass-Through and Competition

We study the pass-through to retail prices of four major changes in taxes for petroleum products (three increases and one subsequent decrease). We use daily pricing data from gas stations on small Greek islands, which define isolated markets with different number of competitors. First, we find that, on average, the pass-through of the tax hikes is five times higher than for the tax decrease. Second, the pass-through of the tax hikes increases with the number of competitors, but that of the tax decrease does not vary with competition (asymmetric competition effect). Third, there is significant asymmetry in the speed of price adjustments. Fourth, the asymmetric adjustment of retail gasoline prices cannot be explained by tacit collusion and the evidence points to search as the most plausible explanation.





Genakos, Christos


Empirical Industrial Organization, Health Economics, Energy Economics


Doctor of Philosophy (PhD)

Awarding Institution

University of Cambridge