JUST A FEW years ago, the term “infrastructure” held little meaning for most people. Today citizens and policymakers alike increasingly subscribe to the notion that we suffer from an “infrastructure crisis,” marked by deteriorating highways, bridges, and sewers. News stories regularly describe an infrastructure that is “rotting,” “crumbling,” or “collapsing.” This conclusion is bolstered by historical and international comparisons of capital-investment spending, which ostensibly demonstrate a persistent national failure to invest in public works. Meanwhile, the recent recession has added urgency to calls for a massive effort to boost public capital spending, create new jobs, and restore our infrastructure to its previous glory. President-elect Clinton’s plan for “’Putting People First” calls for spending an additional $20 billion a year on everything from rebuilding highways to constructing high-speed rail lines.  And the nation’s mayors have identified more than $26 billion in immediate public works projects to help lead cities and the nation out of recession.