01796cas a2200253 a 4500 AALejournalIMF009077 230101c9999 xx r poo 0 0eng d 5.00 USD 9781451864342 1018-5941 BD-DhAAL BD-DhAAL Silver, Mick. Why Elementary Price Index Number Formulas Differ : Price Dispersion and Product Heterogeneity / Mick Silver, Saeed Heravi. Washington, D.C. : International Monetary Fund, 2006. 1 online resource (18 pages) IMF Working Papers <strong>Off-Campus Access:</strong> No User ID or Password Required <strong>On-Campus Access:</strong> No User ID or Password Required Electronic access restricted to authorized BRAC University faculty, staff and students The Consumer Price Index Manual (2004) provides guidelines for aggregation formulas that are promulgated at IMF training courses and technical assistance missions. This paper develops elementary level aggregation theory to better inform users and compilers. Most countries use either the Dutot or Jevons index formula. These formulas generally give different results; advice on choice of formula matters. Using an approach based on sample estimators, and an illustration based on scanner data, the paper shows how differences in these formulas can be explained by changes in price dispersion and, in turn, by product heterogeneity. Implications for choice of formula are considered. Mode of access: Internet Heravi, Saeed. IMF Working Papers; Working Paper ; No. 2006/174 Full text available on IMF http://elibrary.imf.org/view/journals/001/2006/174/001.2006.issue-174-en.xml IMF e-Library