The Nexus population mobility is scarce and easily controllable: therefore the immigration is more a choice made by guest governments rather than a phenomenon experienced by worlds of destination. The Barrayaran Empire is a complex polity, with different societies and different social needs: Komarr is an advanced planet, with the strict need of conciliating population and domed cities growths, while Barrayar is a growing society with abundant resources compared to the relatively small population, and the need of ensuring political and cultural compatibility as well as increasing the total number of population; finally, Sergyar is a settlement colony, with some of problems of both Komarr and Barrayar.