Governments build things — roads, railways, dams, power plants — and public investment is where the largest sums, the biggest waste, and the most spectacular failures live. Public investment management (PIM) is the system for choosing and delivering those projects well. This module covers the PIM cycle, the efficiency gap, and why politically-attractive but economically-useless 'white elephants' get built. It is the budget-side complement to the Cost–Benefit Analysis course.
The PIM cycle and the efficiency gap
Good public investment runs through a cycle: appraisal (is the project worth doing? — the cost-benefit analysis of the next course), selection (choosing which appraised projects to fund within the budget), implementation (delivering on time and budget), and evaluation (did it work? — closing the loop). Weakness at any stage wastes money, and the aggregate waste is enormous.
The efficiency gap (IMF PIMA)
The IMF's Public Investment Management Assessment (PIMA) finds that countries lose, on average, around 30% — and in low-income countries closer to 40% — of the potential value of public investment to inefficiency: poorly-chosen projects, cost overruns, delays, and inadequate maintenance. This is the efficiency gap. The implication is striking: for many countries, the binding constraint on infrastructure is not the amount of money spent but how well it is spent — closing the efficiency gap could deliver as much additional infrastructure as a large increase in investment, at no extra fiscal cost. PIM reform is therefore among the highest-return things a finance ministry can do.
White elephants
Why useless projects get built (Robinson-Torvik)
A white elephant is a project whose costs exceed its benefits — an investment that destroys value. Why are they built, repeatedly and deliberately? James Robinson and Ragnar Torvik (2005) give a political-economy answer: a white elephant can be MORE politically attractive than an efficient project precisely because it is inefficient. An efficient project would be built by any government, so it earns a politician little special credit; a white elephant that only this patron will build, and that delivers targeted benefits (jobs, contracts, rents) to supporters in a way an efficient project would not, creates a credible basis for political exchange and clientelist reward. The inefficiency is the point — it makes the benefit targetable and the patron indispensable. White elephants are thus not mistakes but equilibria of distributive politics (the logrolling and clientelism of the Political Economy & Governance area), which is why they are so persistent and why a purely technical fix is insufficient.
Optimism bias and cost overruns
Even well-intentioned projects systematically come in late and over budget. Bent Flyvbjerg's research on megaprojects documents pervasive cost overruns and benefit shortfalls — costs underestimated and benefits overestimated at appraisal, again and again. Two mechanisms: optimism bias (a genuine cognitive tendency to underestimate costs and overestimate benefits — the 'planning fallacy') and strategic misrepresentation (project promoters deliberately low-balling costs and inflating benefits to get the project approved, knowing that once construction starts it is too committed to cancel — the strategic-misrepresentation problem links to public choice). The corrective, mandated in the UK Green Book and elsewhere, is reference-class forecasting (the Cost–Benefit course's tool): base estimates on the actual outturn distribution of similar past projects rather than the promoter's bottom-up estimate, and apply an 'optimism-bias uplift'.
The appraisal gate
The single most valuable PIM institution is a credible appraisal gate: a requirement that no project above a threshold can be selected or funded until it has passed an independent, rigorous appraisal (cost-benefit analysis) and entered a managed pipeline. The gate is what stops white elephants and unappraised vanity projects from being inserted directly into the budget. Its enemies are political: powerful sponsors who want to bypass appraisal for their pet project, and the temptation to 'direct-appoint' projects outside the system. A gate that can be overridden by political fiat is no gate at all — the same credibility-and-enforcement lesson as fiscal rules. The gate must have teeth and independence to function.
Public-private partnerships
PPPs: the appeal and the trap
Public-private partnerships — where a private partner finances, builds, and operates infrastructure in exchange for user charges or government payments — are attractive because they can bring private finance and efficiency, and (the dangerous part) because they can keep the upfront capital cost off the government's budget and debt today. That very off-budget quality is the trap: a PPP commits the government to long-term payments or risk-bearing (the fiscal-risk and contingent-liability problem of the transparency module), which can be a way to spend and borrow while hiding it from the deficit and debt figures — fiscal illusion in infrastructure form. PPPs can be excellent where genuine risk transfer and efficiency justify them, but they must be appraised on a whole-of-life, value-for-money basis against public procurement, and their fiscal commitments disclosed and accounted for — or they become expensive off-balance-sheet borrowing dressed as private investment. Kenya's and the region's PPP and large-project experience (the SGR being the prominent debate) illustrates both the appeal and the risks.
Exercise
A government proposes a large new prestige railway, championed personally by senior politicians, with an appraisal (produced by the promoter) showing a benefit-cost ratio of 2.5. It will be financed by a PPP/external loan that keeps the cost off the headline budget. Critics call it a likely white elephant. (1) Explain why the promoter's BCR of 2.5 should be treated with scepticism, citing optimism bias and strategic misrepresentation. (2) How would reference-class forecasting change the appraisal? (3) Apply Robinson-Torvik: why might this project be politically attractive precisely because it may be inefficient? (4) Explain the fiscal danger of the off-budget financing and what transparency/PIM safeguards should apply.