Immigration and economic welfare: resource and environmental aspects

"The relation between immigration and the economic welfare of residents is analyzed for resource-rich economies (such as Australia) both under competitive conditions and when various distortions are present. Immigration provides efficiency gains for residents under distortion-free competition for standard 'gains from trade' reasons. Such reasons, however, tend to be ignored by immigration and 'optimal population' theorists who raise the issue of restricting immigration without explicitly referring to the distortions. In situations where distortions and externalities are present, we argue that it is generally preferable to devise policies which specifically target the distortions than to restrict immigration."