中金 • 全球研究 | 2025年日本自民党总裁选举#1：石破首相辞职

Core Viewpoint - The resignation of Japanese Prime Minister Ishiba on September 7, 2025, is expected to lead to a more aggressive fiscal policy and a more accommodative monetary policy from potential successors, which may exert upward pressure on Japanese stocks, depreciation pressure on the yen, and upward pressure on long-term Japanese government bond yields [2][10]. Group 1: Resignation Context - Ishiba announced his resignation, stating that it was an appropriate time following the conclusion of trade negotiations with the U.S. and to avoid potential internal divisions within the Liberal Democratic Party (LDP) [3]. - The backdrop of his resignation includes significant losses for the LDP in the July 20 Senate elections, which typically necessitate accountability from the party leader [4]. - A survey indicated that 103 out of 295 LDP members supported an early presidential election, suggesting a lack of confidence in Ishiba's leadership [4][6]. Group 2: Importance of the LDP Presidential Election - The LDP is the largest party in the House of Representatives, holding 196 out of 465 seats, making the upcoming presidential election crucial as the winner will likely become the next Prime Minister [5]. - The LDP has been the ruling party in Japan for most of the past 70 years, indicating a low likelihood of structural changes in Japanese politics despite the leadership transition [5]. Group 3: Future Election Arrangements - Two potential models for the LDP presidential election are identified: a "complete process" involving all party members, which takes about a month, and a "simplified process" relying on local party branches, which takes 2-3 weeks [6][7]. - The decision on which model to adopt will be made after September 8, with the new president expected to be elected by late September [7]. Group 4: Potential Candidates - In the 2024 LDP presidential election, the leading candidates were Sanna Takachi with 181 votes and Shinjiro Koizumi with 136 votes, indicating their strong support [7]. - Public opinion polls show Takachi and Koizumi as the top choices for the next Prime Minister, with 15.9% and 14.6% support, respectively [7][11]. Group 5: Impact on Financial Markets - Ishiba's economic stance focused on fiscal consolidation and monetary normalization, which has led to a "Ishiba Discount" affecting the Japanese stock market negatively [10]. - The resignation is expected to shift the market dynamics favorably, with potential successors likely to adopt more aggressive fiscal and accommodative monetary policies, although some market impacts may already be priced in [10].