By applying quadratic instead of CES consumer preferences in a monopolistic competition

model with heterogeneous firms, this paper investigates the robustness of the conventional sorting of cross-border active firms, first described by Helpman, Melitz and Yeaple (2004), and finds

thereby an alternative type of sorting: While (sufficiently) productive firms export and more

productive ones engage in foreign direct investment (FDI), the most productive firms do not

undertake FDI, but export again, establishing the so-called sandwich sorting. Evidence for this

type can be observed for investment and services trade patterns.