In recent decades most countries have experienced substantial increases in recycling. During the same period, international trade of recyclable materials between developed countries and developing countries has also grown. Increasingly, waste materials recovered in developed countries are exported for utilization in developing countries. We investigate the causes of this trend,focusing on two materials: paper and lead. Trade patterns of these materials are analyzed for the developed and developing world. We find that countries that have actively participated in trade of recyclables have higher recycling rates than those with closed recycling systems. Other factors that contribute to the intensity of recycline are geographic and economic conditions.