The primary hormone produced by the male testes is testosterone, a steroid hormone important in the development of the male reproductive system, the maturation of sperm cells, and the development of male secondary sex characteristics such as a deepened voice, body hair, and increased muscle mass.
Foreign investments in the US average $2.4 trillion, while American investments in other countries total $3.3 trillion. Consumer spending comprised 71% of the US economy in 2013, and the United States has the largest consumer market in the world. As a result, the US possesses not only the largest economy, but also one of the most stable in the world. Economic History. The United States has had the world's largest national economyânot including the benefit of colonial empiresâsince the 1890s.
In the United States, people also vote on public policies and for the political leaders who set policies that have major economic effects. Some of the most important organizations in the U.S. economy are businesses that produce and distribute goods and services to consumers.or the most part, the United States has a market economy in which individual producers and consumers determine the kinds of goods and services produced and the prices of those products. The most basic economic institution in market economies is the system of markets in which goods and services are bought and sold.