The major benefit of a common currency that has been emphasized is that it facilitates trade (in both goods and services) and investment among the countries of the union (and hence increases income growth within the region) by reducing transaction costs in cross-border business, and removing volatility in exchange rates across the union. A currency is like language (Barro 2001). As a common language facilitates effective communication among people, a common currency could promote trade and investment among countries. In an environment of different currencies, transaction costs, including the costs of obtaining information about prices, would be higher. This would be a disincentive to trade, commerce, and investment.