The convergence of realist and structuralist thinking takes place mainly around the concept of power. Neomercantilists like Gilpin try to understand questions about the dynamics of power, that is, which factors historically define power and why great powers rise and decline. Dependency scholars argued for a structural concept of power, focusing on the bias or the social construction of options in the global political economy which systematically privileges some actors (following the old saying that 'everybody is free to eat at the Ritz and to sleep under the bridge'). Susan Strange uses such an approach for four structures, namely the military, as traditional realists do, production as Marxists stress, a knowledge structure similar to that in Gramscian theories, and particularly finance which she sees as being scandalously neglected in other theories.