New bridges and roads are worth 18% more than we thought

The World Bank studied a bridge between Sweden and Denmark and found that current methods for calculating infrastructure benefits miss a lot. It turns out, planners ignore the economic gains from business travel and services trade, which means they underestimate a project's value by almost a fifth.

Governments and development banks have built infrastructure based on cost-benefit analyses that mostly counted commuting. This paper shows that ignoring services trade, like consultants traveling for meetings, means they have been undercounting the real economic upside. Projects that looked marginal might now look like clear winners, especially those connecting regions that can trade services.