This public working paper develops a conceptual and quantitative framework for transforming a portion of African public debt into productive concessionary assets through an instrument called the African Debt-for-Development Concession, abbreviated as ADDC. The paper starts from a historical problem: public debt has expanded globally and in Africa, but many borrowing cycles have not produced a sufficient stock of self-liquidating productive assets. Conventional restructuring, refinancing and relief can reduce liquidity pressure, yet they do not automatically create ports, logistics corridors, energy platforms, industrial zones, digital infrastructure or export capacity. ADDC therefore reframes part of the debt question as a conversion problem: under what conditions can a sovereign claim be reorganised into economic rights linked to a governed productive asset? The paper integrates debt-for-development swaps, sovereign recovery analysis, public-private partnerships, concession governance, special economic zones and institutional economics. Its main contribution is a dual-sided public model: a debtor eligibility logic, a creditor attractiveness logic and a joint viability rule […]