Factor price equalization is an economic theory that suggests that free trade leads to the equalization of factor prices, such as wages and rents, across countries. As countries engage in trade based on their factor endowments, the demand for factors of production shifts, ultimately resulting in similar factor prices globally. This concept is central to understanding the implications of the Heckscher-Ohlin model, which asserts that countries will export goods that utilize their abundant factors of production while importing goods that require factors they lack.