本研究旨在探討政府房地合一稅制宣告，對台灣上市上櫃營建相關產業類股股價報酬之影響。實證中，採用事件研究法，分析2015年房地合一1.0版及2021年房地合一2.0版，在行政院通過、立法院三讀通過、總統公布以及正式施行日等4個階段之宣告效果。再依照台灣經濟新報資料庫產業指數分類，將營建相關產業細分為水泥業、鋼鐵業及營建業等3類，研究其在兩次稅制，在4個宣告階段，不同產業股價是否有顯著異常報酬及累積異常報酬之情形，並據此了解股票報酬與特定事件是否具有關聯性。 研究結果顯示：營建相關產業在行政院通過日及施行日，不管是全部營建相關產業或是細分分別產業，都具有顯著的異常報酬情況，而政策在行政院通過日前，營建相關產業就開始存在有負異常報酬發酵，可見打房政策的消息，已經有提早發散於市場的現象；從分別的產業來看，水泥業影響效果不明顯，鋼鐵業在行政院通過日有最大的負報酬反應，營建業是在政策施行日之後有最大的顯著負平均異常報酬效果。 Taking Taiwan's listed and OTC listed construction related industrial stocks as the research object, this study analyzes the impact of the two announcements of the government's real estate integration policy in 2015 and 2021 on the stock price of construction related industrial stocks in Taiwan. We explore the effect of the announcement and implementation of the two tax systems of real estate integration 1.0 and real estate integration 2.0 in the Executive Yuan, the third reading of the Legislative Yuan, the presidential announcement and the implementation day via event study method. According to the industrial index classification of TEJ database, the construction-related industries are subdivided into cement industry, steel industry and construction industry. We observe and examine the abnormal returns and cumulative abnormal returns in the stock prices on the announcement or implementation date of different industries in four stages under the two tax systems. This information reveal that whether the stock price is related to a specific event. The results show that the construction-related industries have significant abnormal returns on the adoption date and implementation date of the Executive Yuan, whether all the construction related industries or subdivided industries. However, before the adoption of the policy by the Executive Yuan, the construction-related industries began to ferment with negative abnormal returns. It can be seen that the news of the housing policy has spread to the market in advance. From the perspective of different industries, the impact effect of cement industry is not obvious. The iron and steel industry has the largest negative return response on the passing day of the Executive Yuan, and the construction industry has the largest significant negative average abnormal return effect after the policy implementation day.
