The government of the United States, like most national governments, undertakes many activities that affect both the size and the distribution of the nation's income. Some of these activities are the result of policies that are explicitly designed to affect personal incomes—for example, welfare programs that are intended to alleviate poverty, or tax policies that impose higher rates on those with higher incomes. Other policies affect incomes more or less unintentionally, as a by-product of other goals. Examples of this type might include government purchases of goods and services (e.g., weapons systems) that increase the incomes of earners in specific industries or localities, or tax and regulatory policies that affect the returns to certain types of investment.