The decline of per capita consumption is not confined to calories. It also applies to proteins and other nutrients, with the exception of fats where the consumption increased. As incomes rose over this period (1983-2004), these declines are puzzling.
Essentially, per capita calorie consumption is lower at a given level of per capita household expenditure. In other words, there is a steady downward shift of the calorie Engel curve (in which calories are plotted against per capita expenditure).
Deaton and Dreze are emphatic that the downward shift of this curve is due to lower calorie requirements; better health and lower activity levels. As the evidence offered is fragmentary and patchy, this explanation is largely conjectural.
Our study provides further insight on the decline of calorie intake and the reasons but it is conducted over a shorter period (i.e. 1993-2004).
Our explanation is embedded in a standard demand theory framework, with food prices and monthly per capita expenditure (in 2004 prices) cast in a pivotal role. A presumption is that people make informed food choices based on flavour, packaging, variety and nutritional content.
Given this, it is meaningful to talk about calorie, protein and other nutrient demand functions. Food prices influence choice of commodities directly through own-price effects as well as through substitutions induced by cross-price effects.
Controlling for these effects, expenditure (as a proxy for income) generally has a positive effect on the demand for a food commodity unless it is an inferior good. Our analysis allows for changes in food demand elasticities with respect to prices and expenditure (proportionate change in food demand/proportionate change in its price) over time.
Finally, we are able to capture the combined effect of changes such as health improvements and less strenuous activity patterns over time. When we refer to changes in calorie demand, these include changes in consumption of food commodities due to changes in their prices, expenditure and other factors.
Our analysis shows the significant negative price effect on cereals (such as rice and wheat) has on calorie demand. Prices of vegetables also affected calorie demand negatively but the effect was larger (in absolute value) over time. So the important point is that the higher the food prices, the lower the calorie demand.
Expenditure had a large positive effect on calorie demand — a 1 per cent increase in per capita expenditure results in a 0.39 per cent increase in calorie demand. According to Deaton and Dreze, other factors (health improvements, and less strenuous activity patterns) contributed substantially to reduction in calorie demand.
While this conjecture is not rejected, it is complementary to our demand-based explanation. During 1993-2004 per capita expenditure stagnated while food prices rose sharply (cereal prices by about 58 per cent and vegetable prices by close to 100 per cent).
Juxtaposing these facts with the food price and expenditure elasticities, it follows that while stagnation of expenditure left calorie demand unchanged, higher food prices reduced it. Lower calorie requirements also contributed to a lower intake but in combination with a lower demand.
But does it really matter why calorie intake fell?
In our view it does, as the policy implications differ vastly. The case for interventions designed to stabilise food prices and expand livelihood opportunities in rural areas is reinforced despite a deafening but misguided chorus that nutritional deprivation is exaggerated or does not matter much.
Raghav Gaiha, Raghbendra Jha and Vani S Kulkarni are working on a joint paper: ‘Demand for Nutrients in India, 1993-2004’ at the Australia South Asia Research Centre at Australian National University.