Most trade-and-growth studies focus on the growth effects of autarky-to-free-trade changes, rather than those of incremental liberalisations. This paper characterizes how the strength and sign of openness-and-growth links depend upon the nature and level of trade barriers. For most types of trade barriers, we find that liberalisation raises or lowers growth depending upon the initial level of the barrier. This suggests empirical studies that pool data from high and low protection nations are mis-specified, and that policy lessons based on autarky-to-free-trade results are of limited use to policymakers.