兩部門異質性廠商下的最適碳稅與資源重分配

Abstract

本論文建立一套具備異質性廠商的多部門一般均衡模型，用以評估不同碳稅政策對經濟與環境的影響。該模型以歐盟27國2019年的資料進行校準，並用來分析四種稅制方案：統一碳稅、差異化稅率、部門豁免，以及小型排放源豁免。結果顯示，碳稅能有效減少排放，並影響生產要素在部門間的重新配置。與未課徵碳稅的情況相比，統一碳稅可將碳排放量減少73%，並使消費增加4.13%。若依部門特性調整稅率，整體福祉可進一步提升。相對地，以豁免為基礎的政策往往會降低減碳效率並導致資源錯置，進而造成福祉損失。然而，若豁免碳排放密集度低且生產力高的部門，則可透過引導資源配置提高整體福祉。至於依廠商規模設計的豁免政策，則會導致資源在部門內部及部門間重新分配。

This thesis develops a multi-sector general equilibrium model with heterogeneous firms to evaluate the impact of different carbon tax policies on economic and environmental performance. The model is calibrated using 2019 data from 27 EU countries and used to analyze four tax schemes: uniform carbon tax, differentiated tax rates, sectoral exemptions, and small emitter exemptions. The results show that carbon taxes effectively reduce emissions and affect inter-sectoral resource reallocation. A uniform carbon tax reduces emissions by 73% and increases consumption by 4.13% compared with no carbon tax. If tax rates are adjusted based on sectoral characteristics, welfare improves further. Sector-based exemption often reduces carbon mitigation efficiency and causes resource misallocation, leading to welfare loss. However, exempting the low-carbon-intensive and high-productivity sector could result in higher welfare through guiding resource allocation. Size-based exemption creates resource allocation within and across sectors.