Why protectionism spells trouble for global economic growth

Economists, however, have generally been sceptical. Since the time of Adam Smith (or maybe even before), open and competitive markets have been seen as most likely to maximize output by directing resources more productively. Broad-based protectionism can also provoke retaliation, which adds further costs in other markets. [...]economists believe macroeconomic policies (fiscal and monetary policies such as interest rates or the budget deficit) to be the natural instruments for achieving macroeconomic goals, such as raising growth and jobs. In a recent study covering the vast majority of developed and developing countries in the world, and half a century'sworth of macroeconomic data, we examined the responses of six key macroeconomic variables to changes in the tariff rate: real GDP, productivity, the unemployment rate, the real exchange rate, the trade balance and inequality.