In the 66 years since World War II ended, virtually all centrally planned economies have disappeared, largely as a result of inefficiency and low growth. Nowadays, markets, price signals, decentralization, incentives, and return-driven investment characterize resource allocation almost everywhere.
This is not because markets are morally superior, though they do require freedom of choice to function effectively. Markets are tools that, relative to the alternatives, happen to have great strengths with respect to incentives, efficiency, and innovation. But they are not perfect; they underperform in the presence of externalities (the un-priced consequences – for example, air pollution – of individual actions), informational gaps and asymmetries, and coordination problems when there are multiple equilibria, some superior to others.