You are Laura Camacho Beltrán, a senior analyst in the Evaluation Unit of Colombia's Ministry of Finance in Bogotá. On Friday 6 February 2026 you must sign your first technical opinion, on a 190-kilometre highway that is asking for national funds, and before you calculate anything you must decide which cost figure to believe.
The situation
On Monday 2 February you found four folders on your desk. The spending committee will review one project per session over the coming months, and the first is the 4G Ruta del Sol highway, Section III: 190 kilometres between the centre of the country and the Caribbean coast, with 12 bridges, 3 tunnels and upgrades to 45 kilometres of existing road. The Ministry of Transport puts the base cost at COP 2,500,000 million and the benefit at COP 420,000 million a year for 25 years: journeys 40% shorter and fewer accidents. The dossier also mentions displaced rural communities and affected wetlands.
The Unit is fourteen economists. Its opinions are not binding, but the committee rarely departs from them, and each one is also graded out of 100 by three senior economists. You arrived in January after five years appraising road concessions for banks. Your head of unit, Rodrigo Salcedo Pinzón, put it this way: "Nobody here asks whether you like the project. They ask whether your assumptions hold."
The template comes with a 6% discount rate, but the cost is your call. The manual offers three approaches: conservative, which adds 25% to the base cost; moderate, which uses it as it stands; and optimistic, which takes off 15%. Julián Arboleda Rincón, who joined from public credit, reminds you of the country's record of overruns on public works. The Ministry of Transport replies that the new 4G concession contracts pass construction risk to the concessionaire. And after the highway come three more dossiers, where everyone will remember the standard you started with.