Presentation on theme: "Optimal Taxation and Food Policy: Impacts of Food Taxes on Nutrient Intakes New Directions in Welfare – OECD, Paris – July 2011 Thomas Allen (University."— Presentation transcript:
Optimal Taxation and Food Policy: Impacts of Food Taxes on Nutrient Intakes New Directions in Welfare – OECD, Paris – July 2011 Thomas Allen (University of Perpignan, CIHEAM/IAMM-MOISA and INRA-ALISS) Olivier Allais (INRA-ALISS) Véronique Nichèle (INRA-ALISS) Martine Padilla (CIHEAM/IAMM-MOISA)
Outline of the presentation Background Research objectives Methodology Results Discussion
Background Increase in the prevalence of obesity and overweight in France since 1990 (Obépi, 2009); Higher risk of illnesses for which nutrition is an essential determinant, among the low-income groups (InVS, 2006) Nutrient-rich food are associated with higher diet costs and energy-dense food with lower costs (Darmon et al., 2007); Public Health authorities’ questioning and academic discussion on the prospect of potential « fat taxes ».
Research Question How best to design a fiscal policy improving households’ allocation of goods in terms of nutrient adequacy to recommendations?
Review of the Litterature Food consumption economics : Estimation of a food demand system to capture price elasticities (Deaton et al.) Health studies : Definition of the public health question and tools of analysis (Drewnowski et al.) Public economics: Modelisation of the optimal taxation conditions (Ramsey, Murty et al.)
Optimal taxation model Ramsey's model (1927) s.c. Taxes' objective: Raise funds. Planner's ojective: Maximise social welfare under the constraint that tax revenue covers a given level of public expenditure.
Optimal taxation model Inverse elasticity rule Ramsey rule: The reduction in demand for each good, caused by the tax system, should be proportional for each good. Inverse elasticity rule: Optimal tax rates on each good should be inversely proportional to the good’s own–price elasticity of demand.
Optimal taxation model Application to a nutritional policy objective Taxes' objective: Transforming consumption behaviours. Planner's objectif: Maximise social welfare under the constraint that the overall diet quality of consumers' food basket reach a minimum level in terms of nutrient adequacy to recommendations. s.c.
Optimal taxation model A nutritional quality/price ratio Optimal financing criteria : The optimal tax rates, for each good, are decreasing functions of their own-price elasticity of demand. Optimal adequation criteria: The optimal tax rates, for each good, are decreasing functions of their « nutritional quality/ price » ratio.
Optimal taxation model System of simultaneous equations The maximization program results in a system of equations where each optimal price variation, t k, : Solving this sytem requires to estimate a complete food demand system. Where quali, p and x are vectors of the diet quality indicators, initial prices and quantities associated with each good and e the own and cross price elasticities.
Methodology – Demand model A conditionally linear system Selection of the Almost Ideal Demand System model (Deaton and Muellbauer, 1980): Iterated Least Square Estimator (Blundell and Robin, 1999).
Methodology – Pseudo-Panel Data A panel of scanner data: periods: cohorts: Date of birth/Social status - 27 food groups Group agregation: Homogenous categories in terms of nutritional content (fruits/vegetables fresh/processed, snacks/already prepared meals, vegetable/animal fat, salty/sugary fat). Price construction: 24 clusters of price according to Localisation/Social status.
Nutrient adequacy indicators MAR - Mean adequacy ratio The MAR for a 100g of food i: The MAR for a food basket:
Nutrient adequacy indicators LIM – Score des composés à limiter The LIM for a 100g o food i: The LIM for a food basket:
Nutrient adequacy indicators SAIN – Score d’adéquation individuel aux recommandations nutritionnelles The SAIN for a 100g of food i: The SAIN for a food basket:
Results – Price elasticty of demand Uncompensated own-price elasticities Statistically significant. Negatives. Low and inelastic. Within usual range.
Simulations – Optimal taxation MAR Goods to tax: Fish, meat, poultry, deli meat, snacks, sugar, animal fat, beverages Goods to subsidize: Fruits and vegetables, yoghurt, milk, cereals and starches, potatoes, vegetable fat and salty snacks
Simulations – Optimal taxation LIM Goods to tax: Fruits and soft drinks, deli meat, snacks, mixed dishes, dairy products, cereals and starches, vegetable and animal fat, sweets and salty snacks. Goods to subsidize: Fish, meat, poultry, vegetables, potatoes, water coffee and tea and alcoholic beverages.
Simulations – Optimal taxation SAIN Improvements once calorie intakes are taken into consideration: Mixed dishes are to be taxed; water to be subsidized. Meat are more heavily taxed; fruits and vegetables more heavily subsidized.
Fiscal incidence Welfare losses homogeneously spread over all income groups.
Conclusion Results and policy implications Theoretical result: A « diet quality/price » ratio and an augmented inverse elasticity rule; Empirical results: Mixed evidence supporting food taxation: - Low price elasticities and high tax rates; - Weak convergence on food groups to tax/ subsidize accross nutrient adequacy indicators.
Use of the Lagragian Method to obtain a system of n+2 linear and non-linear equations and n+2 unknowns. with Methodology – Optimal taxation (2)
Methodology – Optimal taxation (3) Using the Lagrangian method: with And assuming a differentiable demand function:
Methodology – Optimal taxation (4) s.c. Increasing the MAR objective until the other constraints collapse is equivalent to: Maximisation Program: