Why is GDP so much more volatile in poor countries than in rich ones? To answer this question, we propose a theory of … technological diversification. Production makes use of different input varieties, which are subject to imperfectly correlated shocks …. In our model, the expansion in the number of varieties provides diversification benefits against variety-specific shocks …

We study how financial market efficiency affects a measure of diversification of output across industrial sectors … and for various levels of disaggregation, we construct a benchmark measure of diversification as the set of allocations of … patterns disappear when we employ "naive" measures of diversification based on the equal spreading of output across sectors …

diversification is less effective when jumps are frequent, unpredictable and strongly correlated. Public supervisors may also mind …