Le résumé en français n'a pas été communiqué par l'auteur. / This dissertation consists of four essays on health and demographic economics. In the first chapter, I explore the implementation of the theory of equality of opportunity (EOp) developed by Roemer (1998) to health in a joint work with Guillem Lopez and Frederic Udina. A common impediment to the achievement of EOp applications with given resources constraints is that it is unlikely that public policies can fully compensate for existing unfair inequalities. This scenario is particularly relevant in the case of health policy, where public spending coexists with a large private spending component. We argue that if social justice is not attainable, social deliberation should not only focus on choosing the circumstances that ought to be compensated but also reflect on which groups suffering unfair inequalities should be prioritized. The second chapter examines the impact of income-related reporting heterogeneity on the measurement of health inequality. While most studies of health inequality rely on self-reported measures of health, recent research has studied the possibility that part of the existing differences in self-reported health could be due to systematic differences in reporting across socioeconomic groups. The concern is that part of the existing inequalities may not be founded on differences in the “true” health status of individuals. In particular, some studies have concluded that reliance on self-reported health might have resulted in an overstatement on the degree of health inequality of some countries. I study the income-related reporting heterogeneity hypothesis in the 2006 wave of the Catalan Survey of Health and I find that the main contributor to health inequality is the disproportionate concentration of the prevalence of reported conditions in lower income groups. The third chapter, joint with Hippolyte d'Albis and Loesse Jacques Esso, studies the trends in mortality convergence across developed countries from 1960 to 2008. While the epidemiological transition has provided a theory behind the expectation of convergence in mortality patterns, our results reject the convergence hypothesis for a sample of industrialized countries. We study the disparities across the mortality distributions of the countries and our sample and find no evidence of convergence towards a common mortality distribution.The fourth and final chapter of this dissertation examines the relationship between unemployment and fertility. I offer a possible explanation for the apparent contradiction between the empirical work that finds a negative relationship between unemployment and fertility and the theoretical work that emphasizes the lower opportunity cost of childbearing while unemployed. I reconcile these perspectives by distinguishing two forms of unemployment. The first form is structural unemployment while the second is cyclical unemployment, a less permanent component of unemployment that is linked to the economic cycle. I study both effects over the life cycle using cohort data on a panel of developed countries. I find that while structural unemployment has an unambiguous negative effect on fertility, reactions to cyclical unemployment depend on the age at which it is experienced.