By construction, the two total effects sum up to the observed raw gap (up to rounding). To make a concrete example, the 90,h/10lh percentile ration in Sweden (the country with the lowest level of wage inequality, and thus with the higher differential with respect to the United States) is 0.873 points lower than in the United States: 0.020 points are accounted for by the composition effect, and the remaining 0.852 are accounted for by the wage structure effect. By construction, the sum of the contribution of each variable of the model delivers the total composition or wage structure effect.19 In the second, third, fifth and sixth column of the tables we report the contribution of two such variables, namely years of education and numeracy skills.