This paper investigates hypotheses about the determinants of trade and investment liberalization with a particular focus on the market access commitments under the General Agreement on Trade in Services (GATS). We identify a positive impact of country size on the absolute coverage ratio, i.e. the ratio of the sum of weighted commitments to the number of possible commitments. Contrary to our theoretical expectations, ‘richer’ countries – i.e., ones with a higher capital-labor ratio – are also more liberal in terms of the absolute coverage ratio. As a further result, we find significant positive spatial interdependence between the coverage ratios of countries.