Abstract: Public Service Motivation (PSM) is one of the most popular concepts in modern public management. Employing high PSM persons so becomes an important issue in public sector, because higher PSM is hypothesised to be associated with higher performance, however, how to motivate individuals with high PSM is a pending question. The core of this question is the interaction of PSM and extrinsic motivators in predicting performance. There are different findings according to the role of extrinsic motivators in PSM- performance relation. Frey’s (1997, 2001) Motivation Crowding Theory was use to integrate these finding. The main purpose of this study is to test hypothesis derived from former studies on extrinsic-PSM-performance relation with a public investment game experiment paradgim. This study used a 12-item scale for measuring PSM and a 2 (extrinsic motivator types: monetary vs honor)×2 (sex: male vs female)×3 (PSM level: Low, Medium, and High) repeated measure design, with the amount of public investments in 3 stages as the repeated dependent variables. This game adapted from Chen’s (2009) public investment dilema, and ask participants to donate for a public project with 20 initial capital. The donation will bring public good and capital increament, and also will bring individual profits or losts. There are three stages: the first for free donation, the second for rewarding donation, the third for free donation after the reward was canceled. Each stage has six trial for participants to donate. Results of this study are as follows: 1) PSM significantly predicted the public investment amount of the third stage and the total amount of public investment; 2) variables such as the extrinsic motivator types, the setup or cancel of these motivators, the sex of participants, and the PSM level infuluence the public investment sigificantly; 3) the setup of moneytary reward could not enhance public donation in this game for most participants, exept for low-level females; while it could bring very negtive conseqence, i.e., bring motivation crowding-out effect; 4) the setup of honor rewards in this game could enhance the investment for male participants in this game, fortunately, the removal of such reward didn’t bring negative effect for male participants, but unfortunately, crowed out PSM for most female participants. In general, crowding-in effect existed only in honor rewards condition for all male participant, not matter high or low the PSM he has, and crowding-out effect existed in both motivating condition for all PSM female participants, no matter high or low PSM she has. The result support those study finding that females are sensitive to social context in public domains, however, only in a kind of negetive way in this study. This study use an experimental paradigm to explore the relation between extrinsic motivation, PSM, sex, and setup or cancel of motivation in predicting performance in public donation game, and the result partly support former findings. These results provided reference for employing newcomers or motivating employees for Chinese human resource managers, especially in public sectors. However, some issues may limit the applying of the results, such as sampling, cultural adaptation, social desiability in measuring, and task designing, etc. Future study should consider this issue to enhance the external validity.

Key words: Public Service Motivation, motivate, Crowding In, Crowding Out, Public Investment Game

摘要： 现代公共管理日益重视公共服务动机，但如何激励公共服务动机，却悬而未决。针对已有研究的局限，采用公益投资博弈的实验范式，考察了激励类型、性别和PSM水平对动机-绩效关系的影响。发现：1）PSM能显著预测公益投资绩效；2）金钱激励撤销后对所有被试均造成了不良后果（动机挤出）；4）荣誉激励能显著提升男性被试的公益投资绩效，且不造成消极后果；但会给女性带来PSM的挤出。未来研究还应考察PSM是否存在内隐层面，并应当考虑文化适合性。

关键词: 公共服务动机, 激励, 挤入效应, 挤出效应, 公共投资博弈