中文摘要：

为考察部门工资差异和工资溢价是否在员工入职之初就已存在，本文基于2013年全国高校毕业生就业状况调查数据，分析了国有部门和非国有部门的起薪差异及其影响因素。通过Heckman两步法修正部门选择内生性后，分部门对毕业生起薪的影响因素进行回归并对起薪差异进行Oaxaca—Blinder分解。主要结论为：首先，国有部门的起薪水平显著高于非国有部门；第二，国有部门和非国有部门内部起薪存在较大差异，毕业生的人力资本和家庭背景是影响起薪高低的主要因素，尤其是人力资本；第三，存在不同的部门起薪决定机制，人力资本对毕业生起薪的影响在非国有部门要大于国有部门，而家庭背景对于提高起薪的作用在国有部门则要大于非国有部门；另外，部门收入差异并不像人们想象的由部门分割或垄断所致，而更多的是部门间人力资本差异的反映，至少从起薪上来看是如此，说明部门工资溢价并非员工入职之初就已存在。

英文摘要：

In order to find out whether the salary differences and wage premium exist at the beginning of employment, the current paper based on the data of national survey of university graduates＂ employment in 2013 analyzed the difference of starting salary between state and private sectors and the influencing factors. Using Heckman two-step estimation, we conducted a regression analysis of factors influencing starting salary and we performed the Oaxaca-Blinder decomposition on starting salary differences. Results show that, first, the starting salary of state sectors are significantly higher than private sectors; second, divergences within state as well as private sectors are considerable; family background and especially human capital are the major factors influencing graduates＂ starting salary; third, there exist different mechanisms of how factors influencing starting salary： human capital has more influence on starting salary in private sectors than in state sectors and family background has more influence in state salary than private sectors; last, the courses of salary differences among sectors are not the isolation and monopoly as was suspected, instead, given the starting salary, it is the manifestation of the differences of human capital among sectors, which means that the wage premium of different sectors are not exist at the beginning of employment.