On the identification of the effect of smoking on mortality

This paper considers the identification of the effect of tobacco on mortality. If individuals select into smoking according to some unobserved health characteristic, then estimates of the effect of tobacco on health that do not account for this are biased. We show that using information on mortality, morbidity and smoking, it is possible to control for this selection effect and obtain consistent estimates of the effect of smoking on mortality. We implement our method on Swedish data. We show that there is selection into smoking, and considerable dispersion around the average effect, so that health policies that aim at decreasing smoking prevalence and quantities smoked might have less effect in terms of average number of years of life gained than previously estimated. We also empirically show that selection into smoking has increased over the last fifty years with the availability of information on the dangers of smoking, so that future studies comparing smokers and non smokers will spuriously reveal a worsening effect of tobacco on health if they fail to control for selection.Health, Duration, Smoking, Selection, Mortality, Life Expectancy, Causality.

Conditional cash transfers, women and the demand for food

We examine the effect of large cash transfers on the consumption of food by poor households in rural Mexico. The transfers represent 20% of household income on average, and yet, the budget share of food is unchanged following receipt of this money. This is an important puzzle to solve, particularly so in the context of a social welfare programme designed in part to improve nutrition of individuals in the poorest households. We estimate an Engel curve for food. We rule out price increases, changes in the quality of food consumed and homotheticity of preferences as explanations for this puzzle. We also show that food is a necessity, with a strong negative effect of income on the food budget share. The decrease in food budget share caused by the large increase in income is cancelled by some other relevant aspect of the programme so that the net effect is nil. We argue that the program has not changed preferences and that there is no labelling of money. We propose that the key to the puzzle resides in the fact that the transfer is put in the hands of women and that the change in control over household resources is what leads to the observed changes in behaviour.Demand, conditional cash transfer, Engel curves, income elasticities, QUAIDS, food, nutrition.

Household Nash equilibrium with voluntarily contributed public goods

We study noncooperative models with two agents and several voluntarily contributed public goods. We focus on interior equilibria in which neither agent is bound by non negativity constraints, establishing the conditions for existence and uniqueness of the equilibrium. While adding-up and homogeneity hold, negativity and symmetry properties are generally violated. We derive the counterpart to the Slutsky matrix, and show that it can be decomposed into the sum of a symmetric and negative semidefinite matrix and another the rank of which never exceeds the number of public goods plus one. Under separability of the public goods the deviation from symmetry is at most rank two.Nash equilibrium, Intra-household allocation, Slutsky

Non cooperative household demand

We study noncooperative household models with two agents and several voluntarily contributed public goods, deriving the counterpart to the Slutsky matrix and demonstrating the nature of the deviation of its properties from those of a true Slutsky matrix in the unitary model. We provide results characterising both cases in which there are and are not jointly contributed public goods. Demand properties are contrasted with those for collective models and conclusions drawn regarding the possibility of empirically testing the collective model against noncooperative alternatives and the noncooperative model against a general alternative.Nash equilibrium, Intra-household allocation, Slutsky symmetry.

Non cooperative household demand

We study non cooperative household models with two agents and several voluntarily contributed public goods, deriving the counterpart to the Slutsky matrix and demonstrating the nature of the deviation of its properties from those of a true Slutsky matrix in the unitary model. We provide results characterising both cases in which there are and are not jointly contributed public goods. Demand properties are contrasted with those for collective models and conclusions drawn regarding the possibility of empirically testing the collective model against non cooperative alternatives and the non cooperative model against a general alternative.Nash equilibrium, Intra-household allocation, Slutsky symmetry.

Demand properties in household Nash equilibrium

Please Note: This paper was updated in July 2007 We study noncooperative household models with two agents and several voluntarily contributed public goods, deriving the counterpart to the Slutsky matrix and demonstrating the nature of the deviation of its properties from those of a true Slutsky matrix in the unitary model. We demonstrate the importance of distinguishing between cases in which there are and are not jointly contributed public goods and provide results characterising both cases. Demand properties are contrasted with those for collective models and conclusions drawn regarding the possibility of empirically testing the collective model against noncooperative alternatives.

Distributional Effects in Household Models: Separate Spheres and Income Pooling

We derive distributional effects for a non-cooperative alternative to the unitary model of household behaviour. We consider the Nash equilibria of a voluntary contributions to public goods game. Our main result is that, in general, the two partners either choose to contribute to different public goods or they contribute to at most one common good. The former case corresponds to the separate spheres case of Lundberg and Pollak (1993). The second outcome yields (local) income pooling. A household will be in different regimes depending on the distribution of income within the household. Any bargaining model with this non-cooperative case as a breakdown point will inherit the local income pooling. We conclude that targetting benefits such as child benefits to one household member may not always have an effect on outcomes.Nash equilibrium; Nash bargaining; collective models; intra-household allocation; local income pooling; separate spheres

Collective and Unitary Models: a Clarification

No abstractunitary; collective; intrahousehold allocation; distribution factors; demand

Distributional effects in household models: separate spheres and income pooling

We derive distributional effects for a non-cooperative alternative to the unitary model of household behaviour. We consider the Nash equilibria of a voluntary contributions to public goods game. Our main result is that, in general, the two partners either choose to contribute to di¤erent public goods or they contribute to at most one common good. The former case corresponds to the separate spheres case of Lundberg and Pollak (1993). The second outcome yields (local) income pooling. A household will be in different regimes depending on the distribution of income within the household. Any bargaining model with this non-cooperative case as a breakdown point will inherit the local income pooling. We conclude that targeting benefits such as child benefits to one household member may not always have an effect on outcomes.