行為經濟學（behavioral economics）崛起自1990 年代，促使經濟學研究轉向關注人類行為，近十年來被大量應用於公共政策領域，催生了「行為政策學」（behavioral public policy）。然而，領域的快速竄起，卻萌生出既有知識與發現過於雜亂混淆等問題。本文旨在界定與釐析行為政策學的理論與應用，聚焦於探討該領域當前最核心的政策工具：推力（nudge）。透過文獻檢閱，試圖討論幾個關鍵問題：行為政策學是新玩意或舊把戲？行為政策學從何而來？行為政策學是什麼？如何透過行為政策學「推」出影響「力」？細析「推力」一定正當且有效嗎？行為政策學只是一時之熱？研究發現行為政策學整合了傳統行為學派與行為經濟學的新元素，強調跨領域觀點與實驗法，可用以測試、設計與校準公共政策；其在西方正處於蓬勃發展階段，目前尚無止息的跡象，相對而言，臺灣的公共行政學門對此領域卻仍在草創的階段。推力訴求以效率方式改變政策標的行為，須具備五個要件，有六種常見策略；其可能存在倫理爭議且未必有效，關鍵在於與政策問題的適配。期使本文的初探能推開後續研究之門，促進國內公共政策領域學子乃至政府部門，對於行為政策學有更好的理解與應用，進而提升領域發展與實質的推動成效。

Behavioral economics -arose in the 1990’s- criticized the assumptions of rational self-interest in traditional economics and led the economic research to transfer its focus to human behaviors. Those findings have been applied more and more to the field of public policies for decades and facilitated the domain of behavioral public policy. However, it is found that the concepts and findings in the field are too messy and confused due to its rapid development. This study aims to clarify the theories and applications of behavioral public policy, with a focus on the core concept “nudge”. Through the literature review, we try to answer several key questions: Is behavioral public policy a new or an old idea? Where does behavioral public policy come from? What is behavioral public policy? How to nudge? Does nudge always work and valid? Will behavioral public policy just be a temporary fashion? Findings indicate that behavioral public policy integrates traditional behavioral approach and new elements of behavioral economics, and focuses on interdisciplinary aspects and experiments methods. It can be applied to test, design and adjust public policy. The field has been booming in the West, while still in the initial stage in Taiwan comparatively. Nudges can be used to change target behaviors effectively. There are five components and six common strategies of nudges. Nudges might be ethically controversial or ineffective, while the key is the adaptiveness to policy problems. This study can contribute to the clarification of behavioral public policy, and benefit to better understanding and application.