When the urban labor market is larger, the cost of search is lower and the efficiency of search is higher, then labor mobility is more adequate and job turnover is more productive with greater job-to-job wage growth. 城市劳动力市场容量越大,搜寻成本越低,搜寻效率越高,所以劳动力流动越充分,更换工作的频率也会越高,进而产生工作间的工资增长效应。