本文探討政策誘發不確定性如何影響異質性家戶世代交疊模型中的家戶儲蓄行為、資本累積與 不均。不確定性來自隨機的資本所得稅，該稅制直接影響家戶儲蓄的稅後報酬。家戶在兩個面向 上具有異質性：技能水準與風險趨避程度。此架構凸顯了預防性儲蓄動機與報酬風險暴露之間的 基本權衡，並因此說明不確定性對儲蓄行為的影響在理論上是不明確的。 為了刻畫這些機制，本文在常數絕對風險趨避偏好與報酬服從常態分配的設定下，從家戶尤拉 方程推導出一個隱含儲蓄規則，並使用隱函數定理分析儲蓄規則的性質。接著，本文將分析延伸 至一般均衡環境，在此環境中，總體資本累積來自異質性家戶儲蓄決策的加總。 數值結果顯示，家戶對政策不確定性、預期稅後報酬與跨期偏好變化的反應，在不同家戶類型 之間存在顯著差異。報酬不確定性上升通常會降低總體資本累積，儘管其背後的家戶反應仍具有 異質性。預期報酬與折現因子的變化也會對儲蓄與不均產生非一致性的調整。此外，等人口結構 與不等人口結構之間的比較顯示，人口組成可以顯著放大總體結果。 整體而言，本文研究結果顯示，財政政策不確定性的總體經濟效果，關鍵取決於家戶異質性、 分配組成與一般均衡回饋，因此無法在代表性家戶框架中被完整理解。;This paper examines how policy-induced uncertainty affects household saving behavior， capital accumulation， and inequality in a heterogeneous-agent overlappinggenerations (OLG) economy. Uncertainty arises through stochastic capital income taxation， which directly affects the after-tax return on household savings. Households are heterogeneous along two dimensions: skill levels and risk aversion. This framework highlights a fundamental trade-off between precautionary saving motives and exposure to return risk， implying that the effects of uncertainty on saving behavior are theoretically ambiguous. To characterize these mechanisms， the paper derives an implicit saving rule from the household Euler equation under constant absolute risk aversion (CARA) preferences and normally distributed returns， and studies comparative statics using the Implicit Function Theorem. The analysis is then extended to general equilibrium， where aggregate capital accumulation emerges from the aggregation of heterogeneous household saving decisions. Numerical results show that household responses to changes in policy uncertainty， expected after-tax returns， and intertemporal preferences differ substantially across household types. Increases in return uncertainty generally reduce aggregate capital accumulation， although the underlying responses remain heterogeneous. Changes in expected returns and discount factors also generate non-uniform adjustments in savings and inequality. In addition， the comparison between equal and unequal population structures shows that demographic composition can significantly amplify aggregate outcomes. Overall， the findings suggest that the macroeconomic effects of fiscal policy uncertainty depend critically on household heterogeneity， distributional composition， and general equilibrium feedback， and therefore cannot be fully understood within representativeagent frameworks.
