The global academic system is hierarchically structured between a center, a semi-periphery and a periphery. We analyze to what extent the position of a country and a university within this hierarchy of scientific reputation shapes doctoral students' chances of international mobility. We conducted an exploratory experimental study using fake applications of international doctoral students sent to German sociology professors, who were asked to serve as supervisors during a planned research visit. Our fake applicants come from the core and periphery of the global academic system: Yale, Pennsylvania State University, National University Singapore, and Vietnam National University Hanoi. The results show that applicants from both US institutions get more positive and more personal feedback than the other applicants. This points to the importance of national scientific reputation. Moreover, we can show that universities' symbolic capital seems to be more important than the quality of a department.