【分析解答题】

原  文：Although the American economy has transformed itself over the years，  certain issues have persisted since the early days of the republic. One is the continuing debate over the proper role for government in what is basically a marketplace economy. An economy based on free enterprise is generally characterized by private ownership and initiative， with a relative absence of government involvement. However， government intervention has been found necessary from time to time to ensure that economic opportunities are fair and accessible to the people， to prevent flagrant abuses， to dampen inflation and to stimulate growth. 

Ever since colonial times， the government has been involved，  to some extent， in economic decision-making. The federal government， for example， has made huge investments in infrastructure， and it has provided social welfare programs that the private sector was unable or unwilling to provide. In a myriad of ways and over many decades， the government has supported and promoted the development of agriculture.