50 likes | 63 Views
This workshop presentation by Carsten Boldsen from UNECE focuses on optimizing the size and distribution of sampled prices in order to ensure representativity, save resources, and reduce response burden. It also explores quick indicators and practical methods for assessing the distribution of prices.
E N D
UNECE Workshop on Consumer Price IndicesIstanbul, Turkey,10-13 October 2011 Session 9: Optimization of the sample Presentation by Carsten Boldsen, UNECE
The size and distribution of the sampled prices • The sample should be regularly examined and updated to ensure its representativity concerning outlets and products • Optimize the sample and avoid over-sampling: - save resources - reduce response burden
The size and distribution of the sampled prices A quick & dirty indicator of the distribution of prices Compare the relative distribution of prices with the weights of the sub-indices/elementary indices Gives a rough idea about the representativity of the prices -But dos not take into account the price development of the sub-indices/elementary indices!
The size and distribution of the sampled prices An easy and practical way of assessing the distribution of prices: • Calculate the average percentage contribution of each elementary index on the 12-months rate of change of the total CPI for a period of a year or more • Compare the relative influence of the elementary indices with the relative distribution of prices • The distribution of price observations should, roughly, correspond to the influence of the elementary indices This is a general measure only – there are exceptions, e.g. for goods and services with very few suppliers.