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The U.S.economy combines private ownership with government regulation.Economic decisions are made by producers，consumers and the government.Producers decide what to produce in order to maximize profit.They also usually shoulder responsibility when bad decisions cause them to lose money or go bankrupt.In order to make their products more competitive，producers work keep quality high and prices low.Inefficient producers are generally forced out of the market where competition is intense.

The government，at both federal（i.e.，national）and state levels，does not decide what to produce or how much to produce，but it does have the power to regulate economy in order to promote public safety and guarantee fair competition.The government also provides services that market cannot provide effectively.

American economic production is mostly carried out by around 20 million companies，commonly known as businesses.Businesses can be either huge corporations employing thousands or tens of thousands of people or small businesses run by a single family.While small businesses are very important to the economy，large corporations generally play a predominant economic role.

Large corporations own most of the capital in the United States and generally make the most important economic decisions.Most of these corporations are national or multinational in scope.Large corporations produce goods and supply services on a vast scale，which requires large amounts of money.To raise funds，many corporations sell stock to the public.A large part of the funds raised through stock offerings come from major financial institutions such as insurance companies，banks and pension funds，but a growing part comes from individuals.

The actions of large corporations have enormous impact on the U.S.economy.If they reduce investment or move capital abroad，the unemployment is likely to increase.If a large corporation goes out of business，its bankruptcy will typically cause many problems for other companies that are its suppliers and customers.The great influence of major corporations on the economy has led the government to pass laws protecting their interests and sometimes to provide help when they are in trouble.

The role of government in the U.S.economy has grown over time.During the early years of American history，most government leaders were reluctant to get involved in business.Starting with the New Deal of the 1930s，government intervention in the economy increased significantly.New Deal legislation extended federal authority in areas including banking，agriculture，and public welfare.As of today，the government has established more than 100 federal regulatory agencies to protect public interests.

Federal government regulation seeks to control the actions of private companies in order to achieve public goals.For instance，the Environment Protection Agency seeks to control water and air pollution，and the Occupational Safety and Health Administration aims to protect workers from dangers they may encounter on the job.The Food and Drug Administration seeks to ban unsafe food and harmful drugs.

In addition to economic regulation，the government also provides services and assistance that the market cannot always provide effectively.Among these are national defense，public transportation systems，universal education，libraries，hospitals，police and fire protection，public parks，public welfare programs and Social Security benefits.In addition，the government provides low interest loans to college students and small businesses，and attempts to promote exports.

The U.S.federal government also takes measures to influence the pace of the nation’s economic activity.The measures can help to accelerate or decelerate the economy’s growth rate by two fiscal policy and monetary policy.