An inquiry into openness in international trade

The ratio of exports plus imports to gross national product may be viewed as a measure of openness in international trade. Constructs indexes for 1967, 1980 and 1988, using this ratio for cross‐country comparison of trade patterns. Analysis of variance and regression reveal that the patterns among countries differ according to levels of income, and that there was a trend towards convergence of the index in the late 1980s reversing an earlier trend towards divergence.