本文探討銀行運用裁決性備抵呆帳進行盈餘管理在不同情境下是否具有不同的盈餘管理目標，同時經由計算盈餘管理後之股票累積報酬，探討不同盈餘管理策略之效果；此外外部融資成本、處分有價證券損益及資本適足率等因素對銀行盈餘管理行為之影響亦有所著墨。研究結果指出，管理前盈餘佳時，銀行盈餘管理目標在平穩化損益，而管理前盈餘不佳時，愈差的績效反而提列愈多的裁決性備抵呆帳，其盈餘管理的目標符合洗大澡理論。不論是損益平穩或洗大澡策略都使銀行股票具有良好的未來累積報酬。當銀行有外部融資需求時會減少提列備低呆帳以增加盈餘水準；在管理前盈餘不佳時，處分有價證券與裁決性備抵呆帳則具有正向關係。

This study investigates the purposes of earnings management when bank's managers' use of discretion in estimating loan loss provisions (LLP) to manage earnings under different scenarios. We also demonstrate the effects of different earnings management purposes by calculating the cumulative stock return after bank managing earnings under different scenario. We find that banks with relatively high pre-managed earnings have positive relation between discretionary LLP and pre-managed earnings and banks with relatively low pre-managed earnings have negative relation between discretionary LLP and pre-managed earnings. The strategies of former and later are consistent with income smoothing and taking a big bath hypothesis respectively. The cumulative stock returns perform well for both the strategies. The need for external financing is negatively significant with LLP. There is a positive relation between gains and losses on the sale of securities and LLP conditional on low per-managed earnings sample.