本研究探討高等教育普及化如何透過文憑訊號傳遞的功能，影響求職者接受教育水準的選擇，以及雇主對於首次求職者薪資之決定。由於訊息不對稱，雇主無法在簽訂工作契約之前確實瞭解首次求職者的能力，因此，教育程度不僅是提升勞動力產出的要素，同時也是傳遞首次求職者能力訊息的一種訊號。透過賽局模型分析以及參數模擬，我們發現高等教育普及化使得文憑取得相對容易時，高能力者被迫選擇超過柏拉圖最適的教育水準，以求與低能力者做出區隔；當高等教育持續擴張造成文憑氾濫，此時的混同均衡會使雇主無法以文憑來辨別首次求職者能力，於是雇主給予社會新鮮人的薪資將減少，體系的均衡將偏離柏拉圖最適，甚至造成社會新鮮人總產出的下降，這是臺灣高等教育普及化的隱憂。

In this paper, we investigate how the higher education universalization affects the choice of the first-time job seeker and the employer through the signaling function of diploma. Because of the asymmetric information, the employer can’t understand the first-time job seeker’s ability absolutely before making a contract. Therefore, education is not only a factor to increase labor productivity, but also a signal to communicate the information of worker’s ability to the employer. By building a game model and using parameter simulation, we find that the job seeker with higher ability will overeducate to make the employer can separate higher ability first-time job seekers from lower ability ones when the expansion of higher education makes it easy to acquire a diploma. Once overabundant diploma due to the expansion of higher education universalization makes the employer can not discriminate higher ability candidates from lower ability ones, the employer reduces the salary of social freshman. Such phenomenon induces the equilibrium away from the Pareto optimality and decreases the total social production.