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.
What Is Economy? An economy is a system of organizations and institutions that either facilitate or play a role in the production and distribution of goods and services in a society. Economies determine how resources are distributed among members of a society; they determine the value of goods or services; and they even determine what sorts of things can be traded or bartered for those services and goods.