Abstract: Public Service Communication is the activity aimed to promote the public interest actions based on the interests of the whole society. In the field of organizational behaviors, incentive strategies includes positive incentives and negative incentives. It was found that positive incentives could strengthen the correct behaviors, while the negative incentives was worked in avoiding the wrong behaviors. This paper aimed to explore whether such positive/negative incentives can work in the domain of public service communication. The prerequisite of the above proposal is the judgement about wasting. It was argued that it would be judged as wrong if the wasted resource was free, but it would be judged as no wrong if the wasted was paid. An university offered perfect conditions of conducting field experiments to test the proposal as its students use water for free but need pay for the electricity in their dormitories. The paper first designed two field experiments to test the above assumptions. Experiment 1 was about water saving. The water is free in the university. It included 3 groups. In the positive incentive group the slogan of “saving water is great” was posted in the bathroom of every dormitories, while in the negative incentive group, the posted slogan was “wasting water is not gentle!”. In the control group, no slogan was posted. The results showed, compared with the control group, the positive incentive slogan did not significantly decrease the amount of water usage (p = .239), but the negative incentive slogan did decrease the amount of water usage significantly (p = .048). Experiment 2 was about electricity saving. Students need pay for the usage of electricity in the university. The experiment design and procedure is similar to experiment 1. The positive (negative) incentive slogans were posted under the electricity meter outside of the dormitory. No slogan was posted in the control group. The data of electricity consumption was recorded during the past 6 months. There was significant difference (p = .038) between the control group and the positive incentive group but no significant difference (p = .902) between the control group and negative incentive group. The experiment 1 and 2 suggested people reacted to the positive and negative insensitive slogan differently depending on the wasted resource was free or charged. The post check revealed wasting free offered goods was indeed recognized as severer “wrong” behavior than wasting the goods charged. To test the hypothesis in one domain, the paper designed a 3 (Slogans: control vs. positive incentive slogan vs. negative incentive slogan) × 2 (payment: free vs. charge) between subjects experiment. In the free condition, the participants were asked to imagine the self-service lunch was for free as it was the university anniversary; but in the charge condition, it described the self-service lunch need payment. Each condition was embedded with positive (vs. negative vs. none) slogans depending on the different slogan group. The participants then evaluated the food saving intension. The results showed, if the lunch was free, the negative slogan was more effective than no slogan (p < .001) and positive slogan (p < .001). On contrast, if the lunch was charged, the postive slogan was more effective than no slogan (p < .001) and negative slogan (p < .001). The three experiments imply that in the public service communication, when the public think “I am not wrong”, we should adopt a positive incentive strategy to persuade the public to take the right actions，otherwise, a negative incentive strategy should be adopted.

Key words: public service communication, positive slogan, negative slogan, wrong/right

摘要： 公益传播是以谋求社会利益为出发点，推动公益行动的传播活动。组织行为中的激励策略，包括奖赏、肯定的正面激励和惩罚、否定的负面激励，正确的行为用正面激励去强化，错误的行为用负面激励去避免。将组织对员工的激励放大到社会对公众的激励，这个假设是否仍能验证？假设能成立的关键在于行为“对错”的判断。某大学学生宿舍用水免费，用电收费，提供了绝佳的现场实验条件。两个现场实验结果验证：浪费水的现场实验中，负面激励比正面激励更有效地节约了用水量；浪费电的现场实验中，正面激励比负面激励更有效得节约了用电量。补充的后测表明，浪费免费的水，被认为是“错的”；而浪费自己花钱的电，则心安理得。第三个节约粮食的实验研究，采用“行为对错判断”（错了vs.没错）ד正负激励”（控制组vs.正面激励vs.负面激励）组间设计，验证了从“社会公德角度的对错判断”是正负激励效果的调节变量。从“个体私利角度的对错判断”与此相反。据此，建议在公益传播中，先从社会公德角度作行为的对错判断，对的行为宜采用正面激励诉求；错的行为宜采用负面激励诉求。

关键词: 公益传播, 正面标语, 负面标语, 错/对