The Role of Economic Factors in Obesity Prevalence and Diet Quality in Spain

Abstract

Obesity is a growing wide spread epidemic all over the world, in developed as well as developing countries. Taking into account its nature as a complex phenomenon affected by different aspects including economic ones, a growing body of literature has examined the effect of economic factors on obesity prevalence and the effectiveness of economic intervention policies in combating it. Many papers argue that economics could be a cure as well as one of the main causes of obesity. Despite the increasing obesity rate in Spain, to my knowledge, no known published research studied the economic factors affecting obesity prevalence, only there are some studies about the prevalence of obesity and the importance of socio-demographic factors that are affecting it (SEEDO and results from the project PORGROW)) in which the role of prices and income was neglected.

The objective of this thesis has been to analyze the relevance of economic factors (mainly income and other socioeconomic characteristics of Spanish households and market prices) on the prevalence of obesity in Spain and to what extent market intervention prices are effective to reduce obesity and improve the quality of the diet, and under what circumstances. In relation to the existing literature, this thesis project is the first attempt in Spain trying to get an overall picture on the effectiveness of public policies on both food consumption and the quality of diet, on one hand, and on the prevalence of obesity on the other hand.

The dissertation is consisted of four papers. The first paper which follows the thesis’ introduction includes a critical review of the literature on the economic approach used to understand and deal with obesity prevalence epidemic, diet quality and public intervention policies. Through the literature review, we also identified the gaps that other papers of the thesis tried to fill. How these gaps were filled by the present thesis and the aforementioned objectives were addressed is the subject the next three chapters of this thesis. In Chapter 3, the determinant factors that affect obesity prevalence were analyzed using a nonparametric approach, the Multivariate Adaptive Regression Splines (MARS). The development and validation process of our new Obesity Specific- Healthy Eating Index (OS-HEI) is discussed in Chapter 4. Chapter 5 deals with the estimation of Spanish consumers demand for food and diet quality, approximated by the BMI, using the EASI demand system and the simulation of the effect of the different price intervention policies on food demand and diet quality in Spain. The thesis ends with some concluding remarks and some suggestions for further research.

Although, this study has been proved to be useful in better understanding obesity prevalence and food demand in Spain, it can be extended through applying recent advances in experimental and behavioral economics. The majority of the papers dealing with the role of economic factors on obesity prevalence, including our papers, found economic factors to have a significant but a quite small effect on obesity prevalence. This suggests that non-economic factors are playing the major role in obesity prevalence. Just and Payne (2009) mentioned that because food decisions are made with little cognitive involvement, food policies designed to appeal to highly cognitive thought (e.g., fat taxes, detailed information labels) are likely to have little impact. With the aim of understanding this little impact of such policies and why consumers sometimes behave in ways that contradict standard assumptions of economic analysis and make decisions that prevent them from reaching rationally intended goals, the use of experimental economics tools in future research could be helpful in this pending question.