|**Table 31 Share of Stapl**<br>_Expenditure Categories_|**e Foods in House**<br>_Share of_<br>_maize, millet,_<br>_manioc and_<br>_yams in food_<br>_expenditure_|**hold Expenditu**<br>_Share of_<br>_rice and_<br>_plantain in_<br>_food_<br>_expenditure_|**re Based on th**<br>_Food share_<br>_in total_<br>_expenditure_|**e 1993 Survey**<br>_Share of_<br>_maize, millet,_<br>_manioc and_<br>_yams in total_<br>_expenditure_|**Results**<br>_Share of rice_<br>_and plantain_<br>_in total_<br>_expenditure_|
|---|---|---|---|---|---|
|_Region_||||||
|Abidjan|12.0|20.1|34.8|4.2|7.0|
|Other Cities|18.4|33.6|43.9|8.1|2.7|
|East Forest|29.8|23.4|56.8|16.9|13.3|
|West Forest|28.7|33.5|59.9|17.2|10.3|
|Savannah|43.5|17.2|61.5|26.8|4.6|
|CPI||||||
|Blue collar worker CPI|10.3|7.2|48.0|4.9|8.3|
|White collar worker CPI|6.8|15.5|38.8|2.6|6.0|

Offsetting this difference, however, is the difference in the composition of food expenditure between Abidjan and the Savannah. Twenty-seven percent of total expenditure in the Savannah was on the four main staples whose prices went down in real terms between 1993 and 1995, compared to 4 percent in Abidjan, and 5 percent in the CPI blue collar basket (table 31). Thus, most of the 27 percentage point difference in the food shares between Savannah and Abidjan is for the four major staples foods whose real price fell between 1993 and 1995. This suggests that, in the Savannah, the price increase in food basket may not have kept up with the overall rate of inflation, and may have more than offset any other differences in the consumption basket, such as the lower expenditure share of lodging, that would tend to raise the Savannah's inflation rate above that of other regions. In any event, information on differences in expenditure shares would need to be complemented by information on region-specific changes in prices, which does not exist.

Another shortcoming is that the same price index is used for both poor and non-poor households, even though expenditure shares differ between the two group. Overall the poor spend 10.8 percentage points more on food, 3.5 percentage points more on lodging and utilities, and substantially less on education, health, transport, and remittances (table 29). About half of the difference on food spending is for the four staple food items. Assuming that the rate of inflation of education, health, transport, and remittances is roughly the same as the overall rate of inflation, then the inflation rate for the poor, although they spend a higher proportion of their expenditure on food, would actually be lower than for the non-poor, taking into account the larger share of expenditure on staple food and lodging by the poor. Thus, the average inflation rate is likely to overstate the actual inflation rate for the poor, and understate it for the nonpoor. The result would be an apparent adverse redistribution effect, as the expenditure of the nonpoor would grow at a faster rate than mean per capita expenditure, while the expenditure of the poor would grow at a slower rate.<sup>27</sup> 27 This abstracts from changes in expenditure shares that arise from substitution effects. If, for example, preferences of the non-poor were such that they substituted goods with the least price inflation for those with the highest, then their true cost of living index would show less inflation that the poor, all other things being equal. For a discussion of true cost of living indices for households of different standards of living, see Deaton (1980). For an empirical application to the problem of defining spatial cost-of-living differences, see Ravallion and van den Walle (1989).

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