In "The Role of Prices in Measuring the Poor's Living Standards," Christian Broda, Ephriam Leibtag, and David E. Weinstein (2009) use proprietary data -- the 2005 Nielsen Homescan dataset -- to analyze differences by income level in the prices paid for food. They find that Nielsen households with incomes above $60,000 pay somewhat more for the same food items than most households with lower incomes, with Nielsen households with incomes above $100,000 paying the most. Based on this finding and additional regression analyses, they conclude broadly that the "poor pay less -- not more -- for the goods they purchase" and that not accounting for this suggests that income inequality may be between 2.5 to 5 percent less than shown by national statistics.
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