The United States is the premier example of a country where people move, and indeed move all over the country, if by doing so they get a better job. This professional mobility also applies to scientists. The country has invented a lot of mechanisms to ease these relocations.

Scientists move because they get a chance to start their own research group. Or they change affiliation because the new place offers a better scientific environment. Or offers a higher salary. For some scientists moving is very simple. A philosopher or a theoretical physicists just has to bring a few books to his new place and he is all set. For a scientist who works for a giant organization as Fermilab bringing his laboratory to the new location is impossible. But how about those scientists that have acquired movable pieces of equipment and apparatuses as a result of their successful grant applications? The scientists need this equipment to be able to pursue their research successfully in the new place. In the United States the rule is very simple: wherever the principal investigator (PI) is going - even if it is abroad - he is allowed to take with him all of his equipment. In my opinion this is the correct attitude.