大幅扩赤字，共和党这份减税案，美债吃得消吗？

Core Viewpoint - The proposed tax reform bill in the U.S. is expected to increase the national deficit by at least $4 trillion over the next decade, raising concerns about its impact on the bond market and long-term U.S. debt sustainability [1][4]. Group 1: Tax Reform Bill Implications - The House version of the tax reform bill is projected to add approximately $3.8 trillion to the deficit by extending the Tax Cuts and Jobs Act (TCJA) and increasing defense and immigration enforcement spending by $320 billion [2]. - The bill includes measures to recover $1 trillion in taxes but simultaneously introduces new tax cuts that could add another $1 trillion to the deficit [2]. - If the Senate does not alter the current wording, the bill could lead to an increase of about $2.5 trillion in the deficit over the next decade, excluding interest payments [2]. Group 2: Long-term Fiscal Outlook - The new tax cuts are set to expire in 2028, but historical trends suggest Congress may extend these cuts, potentially adding another $1.5 trillion to the deficit, bringing the total to $4 trillion [3][4]. - The U.S. borrowing for fiscal year 2024 is expected to exceed $2.5 trillion, with a slight decrease to below $2.1 trillion in 2025, although the actual financing needs may be closer to $2 trillion when accounting for other variables [5]. Group 3: Economic Growth and Deficit Dynamics - The progressive nature of the U.S. tax system means that during economic slowdowns, tax revenues often fall short of expectations, which could exacerbate the deficit if economic growth in 2025 is weaker than anticipated [6]. - Even without the tax reform bill, the deficit is projected to remain at least 6.5-7% of GDP during good economic times, and could significantly increase during economic downturns [6]. Group 4: Bond Market Reactions - Despite a likely slowdown in GDP growth, U.S. bond yields have been rising, driven by inflation concerns and capital outflows from foreign investors, alongside worries about the increasing deficit [7]. - The rising deficit is expected to lead to higher long-term interest rates, which in turn raises future interest payment obligations, creating a feedback loop of concern among bond investors [8].