The central question of this paper is how international trade and specialization are affected by different designs of pension schemes and asymmetric demographic changes. In a model with two goods, two countries and two production factors, we find that countries with a relatively large unfunded pension scheme will specialize in the production of labour intensive goods. If these countriesare hit by a negative demographic shock, this specialization will intensify in the long run, which is contrary to the prediction of the classical Heckscher-Ohlin-Samuelson model. Eventually, these countries may even completely specialize in the production of those goods. The e ects spill over to other countries, which will move away from complete specialization in capital intensive goods as therelative size of their labour intensive goods sector will also increase.