Within or Without? How Firms Combine Internal and External Labor Markets to Fill Jobs
研究了哪些职位更可能通过内部晋升或横向调动而非外部招聘来填补，基于交易成本理论分析了职位特征（如企业特定技能需求、绩效变异性和内部候选人供给）对招聘方式的影响，利用一家大型投资银行七年的员工数据发现绩效变异性和初级与高级员工比例影响内部招聘，但企业特定技能无显著影响。
We examine which jobs are more likely to be filled by internal mobility (specifically, promotions and lateral transfers) than by hiring. Building on the assumptions of transaction cost accounts of employment, we develop a new theory that focuses on the interaction between the problems of evaluating and integrating external hires, on the one hand, and the incentive costs of failing to promote eligible workers, on the other. These arguments lead us to predict how three specific characteristics of jobs—demands for firm-specific skills, performance variability, and supply of internal candidates—affect how those jobs are staffed. Using seven years of personnel data spanning all jobs from the U.S. offices of a large investment bank, we find that jobs with higher performance variability and a larger grade ratio of junior to senior workers are more likely to be filled by internal mobility. We also find evidence that the effects of performance variability are contingent on the grade ratio, affecting staffing decisions only when the firm does not face strong pressures to promote junior workers in order to maintain incentives. Contrary to expectations, we find no effect for firm-specific skills.