If the European Union, Japan and Canada have their way, negotiations for a multilateral investment agreement will begin at the World Trade Organisation meeting in Cancun in September. But many developing countries are doing everything they can to ensure they do not. They are right to do so: an MIA has the potential to cause them serious economic damage.

There is no conclusive evidence that investment agreements lead to increased foreign investment. Since the 1980s, developing countries have signed numerous bilateral investment agreements, yet they receive less than…