Wassily Leontief discovered what became known as the "Leontief Paradox" while testing the Hecksher-Ohlin theory empirically in 1954. The paradox was that the United States, the most capital abundant country, exported labor-intensive goods and imported capital-intensive goods, contrary to the Hecksher-Ohlin theory's prediction. Later studies by Robert Baldwin and others continued investigating this paradox by examining trade patterns between countries.