Insiders versus Outsiders
提出内部人-外部人理论，解释劳动力市场中在职者（内部人）比求职者（外部人）享有更有利就业机会的原因，关键在于企业替换员工时产生的劳动力流动成本。
he insider-outsider theory examines the behavior of economic agents in markets where some participants have more privileged positions than others. Incumbent workers in the labor market, the "insiders," often enjoy more favorable employment opportunities than the "outsiders." The reason for this disparity is that firms incur labor turnover costs when they replace insiders by outsiders. In practice, the distinction between insiders and outsiders is a matter of degree.