The quality of the physical infrastructure in our major cities is just as critical as human capital development in terms of driving long-run growth in productivity and rising living standards. The provision of high-quality and reliable infrastructure network services (like roads, rail and telecommunications) can have significant social, environmental and economic payoffs. Notwithstanding the obvious intuitive connection between infrastructure investment and economic growth, the link between the two is still debated. One reason is that not all infrastructure investment supports growth over the long-term. Building a road or rail line that is not used for instance lowers productivity and economic growth in the long-term. A second reason is tha...