The regional price of junk foods relative to healthy foods in the UK: indirect estimation of a time series, 1997-2009

The paper aims at indirectly estimating a time series of food prices from household expenditure data, focusing on foods considered as ‘junk’ relative to healthy foods. The “big 6” among the HFSS (high in fats, sugar and salt) foods identified by the Food Standard Agency have been selected to compose a target ‘unhealthy’ basket, compared to a ‘healthy’ benchmark aggregate including fruit and vegetables. UK data from the National Food Surveys, the Household Expenditure Surveys and the Living Costs and Food Survey were harmonized and merged to compose a set of household level unit values from 1997 to 2009 for the healthy and unhealthy aggregates. Well-established techniques are then employed to estimate regional prices by disentangling the quality component from unit values. The analysis provides information on the geographical and time heterogeneity of estimated price of the unhealthy basket relative to fruit and vegetable prices.