Chapter 3: How to Interpret ADePT Results
the 90th percentile per capita expenditure and the quantile PCE at the 10th percentile is larger in the rural area (81.6 [2,F]) than in the urban area (79.3 [1,F]) in 2003. The 90/10 measure increases for Georgia and both its urban and rural areas in 2006 [4,F] and [5,A]. Lessons for Policy Makers This table is helpful in holistically understanding inequality across the per capita consumption expenditure distribution. The mean and median are measures of a distribution’s central tendency and the distribution’s size, while the Gini coefficient is a single measure of the overall distribution that does not provide any information about which part of the distribution changed. The four additional quantile PCEs reported in table 3.5 provide information about different parts of the distribution. For example, the Gini coefficient analysis in table 3.1 shows that inequality in the rural area has decreased, whereas inequality in the urban area has increased. Which part of the distribution is responsible for such changes? The Gini coefficient does not provide an answer to this question. A decrease in inequality in the rural area has not been obtained by increasing the income of the poorest because the quantile PCE at the 10th percentile in the rural area fell to GEL 41.0 in 2006 [5,A] compared to GEL 42.2 in 2003 [2,A]. The quantile PCE at the 80th percentile increased from GEL 173.1 in 2003 [2,D] to GEL 175.9 in 2006 [5,D]. In other words, even though the Gini coefficient fell, inequality between the quantile PCEs at the 80th percentile and the 20th percentile increased in the rural area: from 66.0 in 2003 [2,G] to 66.8 in 2006 [5,G], according to the 80/20 measure. Partial Means and Partial Mean Ratios Table 3.6 reports two lower partial means, two upper partial means, and two partial mean ratios, based on the partial means between two periods: 2003 and 2006. Table rows denote three geographic regions: urban, rural, and all of Georgia (rows 3 and 6). Per capita consumption expenditure is measured in lari per month. Columns A and B report two lower partial means (LPM), columns C and D report two upper partial means (UPM), and columns E and F report partial mean ratios. The first partial mean ratio, for example, reports the 90/10 partial mean ratio, computed as (90th percentile UPM – 10th percentile
167