How Is the Liberalization of Food Markets Progressing? Market Integration and Transaction Costs in Subsistence Economies
改进了Baulch的平价边界模型，通过估计交易成本而非外推单一观测值，衡量发展中国家食品市场的整合程度，发现市场整合在粮食短缺期间持续下降。
We propose a modification of Baulch's parity bounds model to measure the market integration of food markets in developing countries. Instead of extrapolating a single observation of transaction costs, we estimate transaction costs. Predicted transaction costs compare well with survey data of traders. Probabilities of market regimes, computed on the basis of predicted transaction costs, fluctuate significantly and do not support fixed regime probabilities over time. The probability of market integration with trade decreases consistently during food shortages, increasing either the probability of no trade or loss-making trade or the probability of profitable but unexploited trade opportunities. The data further support a negative trend in market integration with trade.