The purpose of the CISG is to make it easier and more economical to buy and sell raw materials, commodities and manufactured goods in international commerce. Without the Convention, there is greater room for uncertainty and disputes. The sales law of one country often differs from that of another. In international transactions, there is often doubt about which nation's law controls. Where there is doubt about the rules that apply, the parties cannot be sure of their rights and obligations. Such uncertainty breeds inefficiency and ill will.