Does the law of one price hold in China? Testing price convergence using disaggregated data

This study examines to what extent prices diverge across China and how long it takes prices to converge following idiosyncratic shocks. We consider monthly data using disaggregated goods prices from 36 cities in China. Following [Imbs, J., Mumtaz, H., Ravn, M., and Rey, H., 2005. PPP strikes back: aggregation and the real exchange rate. Quarterly Journal of Economics 120, 1-44.], we use two estimation methods: a fixed effect method when considering goods individually and a mean group estimation specification for a panel including all goods simultaneously. The mean group method also accounts for dynamic heterogeneity across goods. Impulse response functions are obtained to calculate half-lives. With both methods, we find half-lives of only a few months or less, supporting the conjecture that convergence rates within a country are faster than rates estimated in an international context. However, the half-life reported here is still shorter than that for other studies using disaggregated intracountry data. Perhaps a lower degree of specialization and market differentiation in developing countries creates a greater potential for price convergence.