近年國內外研究中國大陸政治經濟學的學者，分別從經濟成長率、固定資產投資成長率等面向，在宏觀層次發現了中國大陸經濟景氣循環與正式政治制度中政府換屆週期趨同的現象。但這個宏觀層次觀察到的「政治經齊景氣循環」(political business cycle, PBC)究竟透過什麼樣的因果機制啟動，卻因為現象太新而尚無定論。本文嘗試從有關PBC研究的一般化理論尋求啟發，對這個宏觀現象提出微觀因果解釋，結合了PBC現有文獻中選舉週期與政治分權的兩組理論，本文主張中國大陸的PBC是由於例行黨政換屆期間權力更替所產生的政治不確定性，引發中央派系政治與地方集體行動兩層機會主義行為交互作用所產生，並以「十六大」時期的經濟波動具體過程分析以及過去四屆政府政治週期對中央與地方投資變化影響的ANOVA測試來證明這個微觀因果機制的運作。我們發現這個具有「中國特色」的PBC與西方民主國家的PBC其實有截然不同的微觀運作基礎：前者主要是地方政府面對中央政府控制投資擴張暫時失靈的集體行動困境所產生的機會主義行為所引發，而後者則是面對選舉壓力的民選菁英為個人短期政治目的所產生討好選民的機會主義行為所致。 Recently, observers of Chinese political economy, through examining either the economic growth rate or the growth rate of fixed asset investment, have found a synchronization of business cycle and the power transition in formal political institutions. Yet there is no consensus among these observers on what is the casual mechanism working behind this phenomenon. Seeking inspiration from the general theories of ”political business cycle,” this article intends to provide a causal mechanism through a micro-level analysis. It argues that the ”political business cycle” we observed at an aggregate level is caused by the interaction of bureaucratic opportunism at two levels. At the top of the bureaucracy, power transition during a government turnover period leads to the intensification of factional politics. At the second tier of a bureaucracy, power transition results in a collection action problem. The political uncertainties during power transition therefore cause opportunistic behavior while controlling for inflation. The paper will combine both qualitative and quantitative studies to illuminate the logic: it will first do a process-tracing analysis on the political business cycle during the 16th Party Congress and then conduct an ANOVA test of the correlation between political cycle and investment cycle of both central and provincial governments. Our findings shows that the mechanism behind the political business cycle in China is totally different from the one in Western democracies: the former is caused by an exaggeration of collective action problems in the central government's inflation control; the latter results from elected officials' short-term political calculation facing of electoral competition.