More populous countries have more business travel in both directions, but the volume is less than proportional to their population: a country with 100% more population than another has only about 70% more business travel. This suggests that there are economies of scale in running businesses that favor large countries.
By contrast, a country with a per capita income that is 100% higher than another receives 130% more business travelers and sends 170% more people abroad. This means that business travel tends to grow more than proportionally with the level of development.
While businesspeople travel in order to trade or invest, more than half of international business travel seems to be related to the management of foreign subsidiaries. The global economy is increasingly characterized by global firms, which need to deploy their know-how to their different locations around the world. The data show that there is almost twice the amount of travel from headquarters to subsidiaries as there is in the opposite direction. Exporters also travel twice as much as importers.
That is from Ricardo Hausmann, with further interesting points.