the long-run demand system. Appendix D shows the results. Although these food
categories are very demanding in terms of quantity, in views of their cultural im-
portance in the Mediterranean area, estimations are close to the benchmark model.
Note that, in both estimations, the dimension of the cross-price elasticities are re-
duced, revealing how these ”new aggregate” food categories show small changes in
own or cross-prices. This result is in line with the low consumption responses to
changes in prices of bread, pasta and olive oil founded by Conforti et al. (2001).
Clearly, however, the impact of changes in relative prices is not equally spread
over the individuals of a society. As described above, inequality may arise from
a heterogeneous consumption response among individuals as relative healthy and
unhealthy food prices evolve. This implies a growing disparity in food access and
calls into question the indiscriminate public health policies generally used to prevent
obesity and overweight in Italy.
Table 5 lists the results of the long-run demand systems specified according to
gender and socio-economic group, obtained by aggregating household expenditures
for food and residual categories by RPI.
Focusing attention on the dimension of elasticities of substitution, η21k and η12k ,
only for individuals who belong to the high education group, we find that the coin-
tegration rank is not exactly identified. Appendix C, reports the results of the
cointegration tests analytically reported for each sub-group. It should also be noted
that the computed elasticities of substitution for people above the relative poverty
threshold and for the younger age class (age less 35) appear to be not statistically
significant.
Besides these exceptions, our estimations contain several points of interest. First,
cross-price elasticities for female household heads (0.08) indicate that the (net) effect
of substitution of unhealthy foods for healthy foods, given changes in relative prices,
is less than half in basis points of the effect for male household heads (0.18). This
result partly emerges in Figure 3 (first panel), in which the sharp increase in relative
healthy versus unhealthy food prices for female household heads does not affect
changes in consumption or total calorie intake. Women are therefore able to keep
their previous habits of eating. These findings are confirmed by the annual report
of the multipurpose survey, ISTAT (2007), in which an increase in body weight is
mainly found in males13 .
13 The results of a greater propensity towards healthy food purchases find indirect confirmation by the greater
control of women’s weight with respect to those recorded for men, and by the low perception of being underweight
of Italian women. These findings are in line with those obtained in France (Etile, 2007; de Saint Pol, 2009).
20