In this paper we highlight aspects related to the links between international migration, foreign tied aid and the welfare state. We model migration as a costly movement from an aid-recipient developing country with low income, poor infrastructure, and no welfare system, towards a rich donor,...

The paper studies insurance with moral hazard in a system of contingent-claims markets. Insurance buyers are modelled as Cournot monopolists or oligopolists. The other agents condition their expectations on market prices, as in models of rational-expectations equilibrium with asymmetric...

The paper develops an integrated model of optimal nonlinear income taxation, public-goods provision and pricing in a large economy. With asymmetric information about labour productivities and publicgoods preferences, the multidimensional mechanism design problem becomes tractable by requiring...

This paper considers the identification and estimation of hedonic models. We establish that in an additive version of the hedonic model, technology and preferences are generically identified up to affine transformations from data on demand and supply in a single hedonic market. For a very...

With reference to the EU enlargement, a framework is derived which allows the study of the effect of unemployment benefits on the migration decision. While benefits simply increase the expected gain for risk neutral individuals, they work as an insurance device for risk averse migrants; the...

This paper investigates four topics. (1) It examines the different roles played by the propensity score (probability of selection) in matching, instrumental variable and control functions methods. (2) It contrasts the roles of exclusion restrictions in matching and selection models. (3) It...

Previous migration facilitates future population moves, a phenomenon called network migration. However, thus far, network migration has been closely linked to network externalities. In contrast, this paper argues that the incumbent migration population can actively impact on future migration...

This paper summarizes our recent research on evaluating the distributional consequences of social programs. This research advances the economic policy evaluation literature beyond estimating assorted mean impacts to estimate distributions of outcomes generated by different policies and determine...

The paper provides a new proof of the positivity of the optimal marginal income tax, in a more general model, under weaker assumptions. The analysis focusses on the (weakly) relaxed problem in which upward incentive constraints are replaced by a monotonicity condition on consumption. Without...