Most developing countries lack spatially disaggregated price data, despite the importance of spatial transactions costs in these settings. We experimented in Vietnam with a new way of obtaining disaggregated price data, using local expert knowledge to derive the mean and variance for prices of 64 items in over 1000 communities. We use these prices to calculate regional cost-of-living indexes. These provide a better approximation to benchmark multilateral price indexes calculated from traditional market price surveys than do two no-price methods, based on using food Engel curves to derive deflators and based on unit values (survey group expenditure over group quantity).
John Gibson & Trinh Le, 2018. "Improved Modelling of Spatial Cost of Living Differences in Developing Countries: A Comparison of Expert Knowledge and Traditional Price Surveys," Working Papers in Economics 18/08, University of Waikato.