This paper examines how technological progress, structural transformation, and international trade shaped the evolution of the skill premium across 37 countries at different stages of development from 1995 to 2009. I argue that observed patterns of structural transformation mask competing forces that operate in opposite directions, a feature that is particularly strong in developing economies where sectoral skill intensities differ sharply. In such settings, the rising share of college-educated workers and skill-biased technological change should, absent offsetting forces, reallocate workers toward sectors less reliant on college-educated labor, such as agriculture. The fact that workers instead moved away from agriculture implies that technological progress in this sector was especially fast, lowering relative prices of agricultural goods and driving up the skill premium. Calibrating a multi-sector model, I find that technological progress raised the skill premium by 152% in low-income countries, compared with 38% in middle- and high-income countries. By contrast, changes in trade patterns played only a minor role in most cases.