6There is a related field dealing with herd effects. Network effects are not exactly the same as herd effects as the latter is related with signaling (“I will go where I have observed others go, because all those who went before me cannot be wrong, even though I would have chosen to go elsewhere.” Epstein (2008)). So, herd effects might lead to ethnic clustering and thus network effects with respect to integration and assimilation in the the host society. But, in migration destination choices herd effect and network effects are different from each other. As herd and network effects are difficult to discern in migration choices and herd effects matter less for adjustment in the host society, we do not consider herd effects in this review.