[182 PONTIFICIAE ACADEMIAE SCIENTIARVM SCRIPTA VARIA - 28 
households in ascending order of level of living, as measured, roughly, 
by per capita consumption expenditure, and dividing the sample (or 
the estimated population) into a suitable number (say, 100, 50, 25, 
20, 10 etc.) of groups, called « fractile groups » each consisting of 
the same number of percentiles (1%, 2%, 4%, 5%, 10% etc.) of the 
sample, and then finding elasticities in terms of the fractile groups. 
These elasticities (or their ratio) seem to be fairly steady; by putting 
in current prices one can then immediately get income-elasticities in 
money term at any point of the range. 
Some interesting points have come out in India about the pattern 
of change of consumption (in physical or money terms) of certain 
commodities with increasing levels of living as measured by the per 
capita consumption expenditure. For certain commodities this pat- 
tern is quite different in urban and rural areas; for example, for 
foodgrains. The interesting point is that, over a period of 10 years, 
the pattern of consumption of foodgrains in urban areas and the 
pattern in rural areas have been entirely different, but both have 
remained practically steady. With the increase of income (in the 
sense of national income or of households) in a country like India 
which is very poor, or with an improvement in the supply position 
of foodgrains, the per capita average consumption of foodgrains of 
the whole population may go up or some times, with increasing prices, 
may go down, but the pattern remains the same. Of course we are 
interested in this, particularly from the point of view of inequalities. 
The National Sample Survey of India, which covers the whole of 
India, has at least two inter-penetrating sub-samples giving two in- 
dependent estimates; and also, of course, a combined estimate by 
pooling the sub-samples. Using a graphical representation (in the 
form of distribution of per capita consumption, or concentration cur- 
ves or in other ways) the difference between the curves based on the 
two sub-samples gives a non-parametric and completely invariant 
error area with which the analysis can be carried very far; I discussed 
it in another paper. From our own experience I fully agree with the 
points made by Prof. Jonson in his paper. 
As regards the supply position, I think in an underdeveloped 
16] Johnson - pag. 42