Migration is a complex process, involving the movement of large numbers of people between different jurisdictions for very different reasons that are liable to change in response to circumstances and in response to the policy regime that confronts them.  Migration to Ireland is made up of diverse groups which are in themselves internally diverse and whose attitudes reflect a variety of moral, cultural and religious principles. In this project, we will develop a model to evaluate policy outcomes for work-based visa applications in Ireland. In any such large scale system, individual behaviour and circumstance will vary widely. Thinking through all the possible combinations of  conditions and behaviours that may lead to a cumulatively deleterious impact on communities is impossible. Some policies that are well-intentioned when conceived may turn out to have ethically indefensible effects. Despite this, the need to make policy does not go away and, at times, must be done in a quick and responsive manner, such as the economic and social response to the pandemic.