摘要：Why is GDP growth so much more volatile in poor countries than in rich ones? We
identify four possible reasons: (i) poor countries specialize in more volatile
sectors; (ii) poor countries specialize in fewer sectors; (iii) poor countries
experience more frequent and more severe aggregate shocks (e.g. from
macroeconomic policy); and (iv) poor countries' macroeconomic fluctuations are
more highly correlated with the shocks of the sectors they specialize in. We
show how to decompose volatility into these four sources, quantify their
contribution to aggregate volatility, and study how they relate to the stage of
development. We document the following regularities. First, as countries
develop, their productive structure moves from more volatile to less volatile
sectors. Second, the level of specialization declines with development at early
stages, and slowly increases at later stages of development. Third, the
volatility of country-specific macroeconomic shocks falls with development.
Fourth, the covariance between sector-specific and country-specific shocks does
not vary systematically with the level of development. We argue that many
theories linking volatility and development are not consistent with these
findings and suggest new directions for future theoretical work.
