The previous course established that policy is the equilibrium outcome of interested actors inside institutions. Public choice is the body of theory that models those actors and institutions formally. Born at the University of Virginia in the 1960s with James Buchanan and Gordon Tullock, it is, in Buchanan's own phrase, 'politics without romance' — the refusal to assume that people become selfless the moment they enter a voting booth or a ministry.
The symmetry assumption
One behavioural model, two arenas
Welfare economics models the private sector as self-interested and the public sector as a benevolent planner correcting its failures. Public choice insists on symmetry: the voter, the politician, and the bureaucrat are the same kind of agent as the consumer and the firm — rational, self-interested, responding to incentives. This is not the claim that everyone is venal; it is the claim that you should not assume away self-interest in politics when you would never assume it away in markets. The asymmetry was an analytical double standard, and public choice removed it.
The consequence is immediate and was the theme of the last course: you cannot infer that a market failure will be fixed just because fixing it is efficient. Government is not a vending machine that dispenses optimal policy; it is another arena of strategic interaction whose outcomes must be derived, not assumed. Public choice is the toolkit for deriving them.
Two branches
- Positive public choice — how do collective-decision mechanisms actually behave? How does majority voting aggregate preferences? How do legislatures, bureaucracies, and interest groups produce the policies we observe? This is the analysis of the in-period game, given the rules.
- Constitutional political economy — what rules should we choose for making collective decisions, before we know our position in the game that follows? This is the analysis of the rules themselves, and it is the normative heart of the Virginia school (the subject of module 8).
The Wicksellian root
Buchanan traced his project to the Swedish economist Knut Wicksell (1896), who made two moves that organise the whole field. First, he insisted that the tax side and the spending side of the budget be considered together: a public good is only worth providing if citizens would willingly pay for it, so decisions about what to spend cannot be divorced from who bears the tax. Second, he proposed (approximate) unanimity as the benchmark for a legitimate collective decision — if a project genuinely makes everyone better off, a properly designed tax-and-spend package could secure everyone's consent. Departures from unanimity are where one group is made to pay for another's benefit, which is exactly what the rest of public choice studies.
Why Wicksell still matters for African budgeting
The Wicksellian discipline — tie each spending decision to a visible financing decision — is precisely what is missing when budgets are financed by debt or donor money rather than by taxes citizens feel. When the spending is visible and the cost is hidden, the link Wicksell demanded is broken, and over-spending follows. We formalise this as 'fiscal illusion' in module 7.
What public choice is not
Public choice is sometimes read as an anti-government ideology. It is better understood as a method. Its founders were classical liberals, and the method does tend to reveal government failures the welfare-economics frame assumes away — but the same tools explain when collective decisions work well, and the constitutional branch is fundamentally constructive: it asks how to design rules that channel self-interest toward good outcomes, exactly as a well-designed market does. Use it as a lens, not a verdict.
Exercise
A presidential candidate promises free university education, a new referral hospital in every county, and no new taxes, to be financed by 'cutting waste and corruption'. (1) Analyse the promise using the symmetry assumption — model the candidate as a rational vote-maximiser rather than a benevolent planner. (2) Apply the Wicksellian discipline: what is missing from the proposal, and why is its absence politically attractive? (3) Public choice is accused of cynicism here. Restate the analysis to show it is positive (predictive) rather than merely cynical. (4) What institutional reform would force the Wicksellian link the promise evades?