Every problem in this course — cycling majorities, budget-maximising bureaus, pork, capture, deficit bias — is a failure of the in-period game given the rules. The Virginia school's constructive response is to move up a level: if the game produces bad outcomes, change the rules of the game. This is constitutional political economy, and its most developed application is the fiscal rule — a self-imposed constraint that ties a government's hands against its own future temptations.
Rules rather than discretion
The case for rules rests on the time-inconsistency result from the previous course (Kydland-Prescott). A government that retains full discretion will, each period, face the temptation to over-spend, borrow, and defer — and rational citizens and markets, anticipating this, price in the bias (higher interest rates, weaker investment). A credible rule that removes the discretion can make everyone better off, including the government, by making the commitment believable. The reform is not about distrusting this government; it is about binding all future governments, including ones with worse incentives.
Fiscal rules as commitment devices
A fiscal rule is a numerical constraint on a budget aggregate, written into law or the constitution to be hard to change. The four families: • Balanced-budget / deficit rules — cap the deficit (e.g., Germany's Schuldenbremse 'debt brake'; the EU's 3%-of-GDP reference). • Debt rules — cap the stock of debt (e.g., a debt-to-GDP ceiling or 'anchor'). • Expenditure rules — cap the level or growth of spending. • Revenue rules — set floors/ceilings on revenue or earmark windfalls. The point of all four is to convert the breakable promise 'we'll be prudent' into a constraint whose breach is costly and visible — moving fiscal policy from discretion toward rules.
The design trade-offs
No rule is free. A rule rigid enough to bind reliably is also rigid enough to bite at the wrong moment — forcing pro-cyclical austerity in a genuine recession or after a drought or pandemic. A rule flexible enough to accommodate shocks invites the government to declare every year exceptional. The design problem is to be binding in normal times and flexible only for true shocks. The standard solutions:
- Cyclically-adjusted targets — constrain the structural balance (stripping out the cycle) rather than the headline balance, so automatic stabilisers can work in a downturn without breaching the rule.
- Escape clauses — pre-specified, narrowly-defined conditions (deep recession, natural disaster, pandemic) under which the rule is temporarily suspended, with a defined path back. Pre-specification is what stops the clause from swallowing the rule.
- Independent fiscal institutions — fiscal councils or parliamentary budget offices that monitor compliance, validate the forecasts (governments otherwise use optimistic forecasts to appear compliant), and raise the political cost of breach. Enforcement by an independent referee is what gives a rule teeth.
- Transparency — published accounts, off-budget items brought on-budget, and disclosed contingent liabilities, so the rule constrains the true fiscal position and not just the headline number.
Why rules get breached: the Kenyan case
Kenya's Public Finance Management Act (2012) embodies the agenda: fiscal-responsibility principles, a development-spending floor (at least 30% of expenditure on development), and a debt ceiling later reformulated as a debt anchor (a target for debt as a share of GDP). In practice the numerical debt limit was repeatedly raised and then converted to an anchor as it was approached, development-spending shares were missed, and headline compliance was flattered by optimistic growth forecasts and off-budget contingent liabilities. The episode is a textbook illustration of why rules fail when the conditions for credibility are absent.
A rule is only as good as its enforcement
A fiscal rule that the same majority which it constrains can amend by ordinary vote is not a binding rule — it is a statement of intent. Credibility requires that breach be costly: entrenchment (hard to change), an independent referee that calls the breach publicly, forecasts validated by someone other than the Treasury, and transparency that prevents evasion through off-budget vehicles. Where these are missing, the rule becomes a ceiling that rises whenever it is touched — present in law, absent in effect. Constitutional economics is not the drafting of numbers; it is the engineering of credible enforcement around them.
The honest assessment
Fiscal rules are not a panacea, and the cross-country evidence is mixed: well-designed, well-enforced rules (with independent councils and sensible escape clauses) are associated with better fiscal outcomes, but poorly-designed or unenforced rules mostly generate creative accounting. The value of the constitutional-economics lens is not that rules always work; it is that it correctly diagnoses the problem as structural — a failure of the in-period game's incentives — and therefore looks for the remedy in the right place: the rules, their entrenchment, and their enforcement, rather than in the character of the current finance minister.
Exercise
A country with a history of deficit bias wants to adopt a credible fiscal rule. Its first attempt — a simple statutory cap on the headline deficit at 3% of GDP, amendable by the same parliamentary majority that sets the budget — is breached in its second year during a drought, then quietly amended. (1) Diagnose why this first attempt failed on at least three design dimensions. (2) Redesign the rule to be binding in normal times but able to absorb a genuine shock like the drought. (3) Explain the role an independent fiscal council would play and why forecasts must be validated externally. (4) Address the deepest objection: if a majority can always amend the rule, can any rule truly bind — and what makes the difference between a rule that holds and one that doesn't?