 One of the major research achievements of the 1990-2010 period was the development of a framework with dynamic search, matching, and bargaining.At the micro level, one sub-discipline eliciting increased attention in recent decades is analysis of internal labour markets, that is, "within" firms (or other organisations), studied in personnel economics from the perspective of personnel management.By contrast, external labour markets "imply that workers move somewhat fluidly between firms and wages are determined by some aggregate process where firms do not have significant discretion over wage setting."