A key assumption in this paper is that aid is given by donor countries completely exogenously, implying that there is nothing that origin countries can do to receive more aid. Immigrants in destination countries can lobby their governments to give out more aid in their origin countries. This presents a reverse causality problem where large migrant stock can actually increase foreign development aid, as opposed to developmental aid increasing migrant stock. My analysis does not control for this, so the results of the analysis may overstate the magnitude of migrant stock in destination countries. Another source of endogeneity are the omitted variables that are related to the error term. My analysis also assumes that the OECD countries allocate aid in countries and sectors where it is most needed. This is not necessarily the case as aid is often used as a foreign policy tool. The underlying incentives of the aid given is an omitted variable and one that is hard to measure. This creates a bias in my analysis by understating the relationship between migration and aid because the allocation of aid is imperfect.