Governments that partner with private firms to deliver infrastructure often create contingent liabilities—promises to cover future payments if private partners fail, traffic falls, or revenues underperform. These obligations are not always recorded as formal debt but can crystallize into explicit fiscal outlays. Eduardo Engel, Ronald Fischer, and Alexander Galetovic Universidad de Chile have shown that many public-private partnership contracts allocate substantial downside risk to the public sector through guarantees, minimum revenue clauses, or termination payments, increasing implicit fiscal exposure.
How contingent liabilities arise
Contingent liabilities emerge from contract design choices within public-private partnerships. When governments offer revenue guarantees, take-or-pay clauses, or refinancing protections, they reduce private partner risk but create potential future payouts for the state. Sometimes these clauses are justified to attract private finance for projects in low-income or politically fragile territories where outright borrowing would be hard to obtain. The International Monetary Fund emphasizes that lack of upfront disclosure and weak project appraisal fuels underestimation of these risks, meaning budgets and debt metrics can misrepresent true fiscal vulnerability.
Fiscal and economic consequences
The principal effect on debt sustainability is that contingent liabilities raise the probability that public debt ratios will surge unexpectedly. If guarantees are called, governments must finance large payments, which can require reallocation from social programs, higher taxes, or new borrowing. This dynamic can compress fiscal space and undermine long-term public investment, with social consequences in regions that depend on service continuity. Antonio Estache has documented that in some countries PPPs shifted project risk back to taxpayers after private partners exited or when demand projections fell short, creating distributional and territorial tensions as central budgets absorb localized failures.
Market perception also matters: investors and rating agencies treat large undisclosed contingent liabilities as a downside risk, potentially raising borrowing costs. Environmental and cultural dimensions intersect when projects—such as hydropower or transport through indigenous territories—face demand shortfalls due to social resistance or environmental remediation costs, turning contingent liabilities into contentious fiscal burdens. Transparent accounting, conservative demand forecasts, and well-structured risk-sharing reduce the probability and size of such liabilities. Policy reforms that require explicit recording of contingent commitments and independent project appraisal strengthen credibility and support sustainable public finances over time.