We estimate the impact of tax incentives for donations to charities in France. We concentrate on two reforms enacted in 2003 and 2005, which raised by 32% the income-tax deduction on gifts to non-profit organisations and charities known as organismes d’utilité publique and organismes d’intérêt général. We use a double-difference estimation strategy. This consists in comparing the changes in donations by different groups of households with similar income levels but different tax statuses due to differences in household size. By using an estimation technique based on censored quantile regressions, we can address the econometric problems arising from the fact that a high proportion of households (80-88%) declare no gifts. This approach also enables us to study the heterogeneity of responses to tax incentives. We find a relatively low price elasticity of donations. This means that the households studied responded weakly to the increase in tax deductions for donations. However, the effect of tax incentives is heterogeneous. All other things being equal, the most generous donors seem to respond to tax incentives more strongly than others.