Overview
- The Hans‑Böckler‑Stiftung’s IMK projects the public debt ratio could approach 100% of GDP by 2050 if defense and security spending remain permanently excluded from the constitutional borrowing cap, up from about 65% most recently.
- Researchers differentiate between the defense exemption and a credit‑financed investment fund, concluding that the latter would lift debt only moderately and temporarily due to growth effects and its smaller scale.
- The study cites a roughly €500 billion investment pot for infrastructure and climate neutrality as supportive of additional output and capacity, which would help lower the debt ratio over time.
- IMK director Sebastian Dullien argues the 2025 reform was misdesigned, granting limited borrowing space for investment while allowing open‑ended credit for defense.
- The institute recommends financing sustained defense outlays primarily through taxes, including a one‑off, purpose‑bound levy on very large fortunes, and reserving long‑term borrowing chiefly for productive public investment.