Amit Khandelwal, Pete Schott, and Shang-Jin Wei have a nice VoxEU column describing their forthcoming AER article on Chinese textile exports under the Multifibre Arrangementquotas. In short, inefficiently implemented policy can substantially amplify the economic distortions introduced by trade barriers:

If trade barriers are managed by inefficient institutions, trade liberalization can lead to greater-than-expected gains. We examine Chinese textile and clothing exports before and after the elimination of externally imposed export quotas. Both the surge in export volume and the decline in export prices following quota removal are driven by net entry. This outcome is inconsistent with a model in which quotas are allocated based on firm productivity, implying misallocation of resources. Removing this misallocation accounts for a substantial share of the overall gain in productivity associated with quota removal.