Modelling physical quantities of food and nutrients consumed from aggregate data – with an application to Finland

Anticipating the impact of changes in economic incentives on dietary quality and nutritional health requires knowledge of how physical quantities of food consumed respond to price and income variations. A problem arises, however, because physical quantities are: 1- not consistent aggregates in demand models; and 2- not measured at final/retail level in national statistics. The paper develops a solution by establishing explicitly the theoretical link between composite demand and physical quantities, from which a novel empirical approach to the estimation of nutrient elasticities is derived. It is applied to Finnish aggregate data from the National Accounts and Food Balance Sheets over the 1975-2006 period, and the results are used to assess the potential effectiveness of several incentive-based nutritional policy instruments.