 It seems to be even more important than the core – periphery exploitation (for example, without taking this mechanism into consideration it appears impossible to account for such things as the demographic explosion in the 20th century, whose proximate cause was the dramatic decline of mortality, but whose main ultimate cause was the diffusion of innovations produced almost exclusively within the World System core).This also suggests a redefinition of the World System core.Within the approach in question the core is not the World System zone, which exploits other zones, but rather the World System core is the zone with the highest innovation donor/recipient ratio, the principal innovation donor.