According to the Washington Consensus, developing countries' growth would benefit from a reduction in tariffs and other barriers to trade. But a backlash against this view now suggests that trade policies have little or no impact on growth. If "getting policies right" is wrong or infeasible, this leaves only the more tenuous objective of "getting institutions right" (Easterly 2005, Rodrik 2006. However, the empirical basis for judging recent trade reforms is weak. Econometrics are mostly ad hoc; results are typically not judged against models; trade policies are poorly measured (or not measured at all, as when trade volumes are spuriously used); and the most influential studies in the literature are based on pre-1990 experience (predating the "Great Liberalization" in many developing countries which followed the GATT Uruguay Round). We address all of these concerns-by using a model-based analysis which highlights tariffs on capital and intermediate goods; by compiling new disaggregated tariff measures to empirically test the model; and by employing a treatment-and-control empirical analysis of pre-versus post-1990 performance of liberalizing and nonliberalizing countries. We find evidence that a specific treatment, liberalizing tariffs on imported capital and intermediate goods, did lead to faster GDP growth, and by a margin consistent with theory (about 1 percentage point per annum). We control for other policy changes and address endogeneity concerns. We also find other patterns consistent with the proposed mechanism: changes to other tariffs, e.g. on consumption goods, though collinear with general tariffs reforms, are more weakly correlated with growth outcomes; and the treatment and control groups display different behavior of investment prices and quantities, and capital flows. Does trade policy liberalization promote economic growth? The question has been central to recent economic policy debates since the dawn of the new era of globalization in the 1990s. Yet the opinions of economists, once quite coherent, are now far from unanimous.In the 1990s the so-called "Washington Consensus" (WC) promoted openness to trade as an essential policy reform to promote growth and higher incomes.2 At first, absent statistical evidence, this revolutionary view garnered support as practitioners looked back on the divergent economic fortunes of the fast-growing export-oriented New Industrializing Countries (NICs) of East Asia and the sluggish inward-looking economies of Latin America. Subsequently, a barrage of cross-country econometric studies seemed to lend weight to this view, including well known and widely cited works by Dollar (1992), Sachs and Warner (1995), Edwards (1998), and Frankel and Romer (1999). It was in this intellectual climate that trade barriers fell in many developing countries in what we might call the "Great Liberalization" of the 1990s.A decade later some feel that previous consensus is lost. A recent survey of the World Bank's self-review Learning from Reform by Rodrik (2006) is entitled "Goodbye ...