"We apply an extension of the Rothbarth approach to estimate the share of household resources accruing to children (i.e., the cost of children) in Ireland. The method also allows us to identify the economies of scale in the household and indifference scales in Lewbel (2003)'s sense. A practical aspect of the present approach is that it does not require price variation. The identification of the children's share requires the observation of adult-specific goods as in the traditional Rothbarth method. We compare our findings to previous results for Ireland."--Author abstract.

Natural experiments provide robust identifying assumptions for the estimation of policy effects. Yet their use for policy design is often limited by the difficulty of extrapolating on the basis of reduced-form estimates. In this study, we exploit an age condition in the eligibility for social assistance in France, which lends itself to a regression discontinuity (RD) design. We suggest to make the underlying labor supply model explicit, i.e. to translate the reduced-form discontinuity in terms of discontinuous changes in disposable incomes. This exercise shows the potential of combining natural experiments and behavioral models. In particular, we can test the external validity of the combined approach. We find that it predicts the effect of a subsequent reform, which extends transfers to the working poor, remarkably well. The model is then used to simulate the extension of social assistance to young people and finds that a transfer program with an in-work component would not create further disincentives to work in this population.