Government debt in several advanced economies is now at its highest level outside wartime, and emerging-market debt has been steadily rising over the past decade. With interest rates no longer at record lows, concerns about fiscal sustainability are growing. The question of how to restore sustainability is hardly new. Policymakers and academics have debated for decades the policies and institutions needed to support fiscal discipline and debt reduction. Many countries adopted numerical fiscal rules. Others strengthened the checks and balances on governments, including through the creation of independent fiscal councils.
But the outcomes have been decidedly mixed: despite some successes, there have been many more failures. That should not come as a surprise, because fiscal policy is ultimately a creature of politics. Decisions on spending and taxation reflect social preferences, economic constraints, distributional conflicts, and electoral incentives. Fiscal sustainability is about reconciling these pressures in ways that place debt on a sustainable path. Given this, there is no easy fix.
Well-designed fiscal frameworks can, however, tilt policy choices toward financial discipline, even when there are other pressures pushing the other way. Research and experience have shown that better design makes a real difference in two areas: assessing debt sustainability and building fiscal rules that survive the political cycle. While the standard framework for assessing debt sustainability is widely accepted, there is a gap when it comes to capturing the feedback loop from fiscal-policy decisions to macroeconomic outcomes that reinforce sustainability.
For example, fiscal tightening can lower debt ratios, but only when done at the right time and in the right way; otherwise, it can weaken growth to the point of damaging sustainability. Moreover, treating all spending as alike can be just as self-defeating: cutting public investment or spending on education or research for the sake of short-term consolidation can lower growth and raise debt ratios over the medium term. Nor is it accurate to claim that any spending will pay for itself through higher growth. What is needed is more guidance on which types of spending have the largest effects on sustainability, and under which conditions.
Rules introduced under market pressure during periods of economic stress often generate only short-term improvements. Once the immediate pressure fades, so does the political commitment to enforce them. Fiscal rules adopted when governments are compelled to build consensus, as opposed to when majority governments simply impose a framework, are more durable. As it turns out, credibility cannot be legislated into existence. The time to build robust fiscal frameworks is before a crisis hits, not after it is too late.
Ultimately, the underlying challenge is the same. Debt-sustainability analysis rests on technical judgments—from growth prospects to returns on different types of spending—that are genuinely difficult to make. And governments have incentives to use optimistic forecasts or selective accounting to shade these judgments in favorable ways. Similarly, the credibility of fiscal rules depends not only on consistent application, but also on sustainability assessments that are both rigorous enough to command trust and resilient enough not to be bent after the fact.
Both areas require research that is technically sound and insulated from political pressures. This underscores the importance of independent fiscal councils, transparent budget processes, and strong technical institutions. Governments, of course, make all fiscal choices, but these technocratic actors raise the quality of those choices, challenge unrealistic assumptions, clarify trade-offs, and anchor rules in analysis that commands wider trust.
Fiscal discipline, in the end, requires more than a framework. It requires public institutions with the technical capacity and the resources to conduct rigorous and honest research. A lack of analytical rigour and integrity produces bad fiscal decisions and short-lived fiscal rules.
The writer is Professor of Economics at INSEAD.
