WASHINGTON—Economic freedom in the United States has dropped to an all-time low due to its deteriorating fiscal health, according to an annual index of the world’s freest economies. The U.S. economic freedom score has declined 1.8 points this year to 74.8, Heritage Foundation, a conservative U.S. think-tank, announced last week. While the U.S. economy remains “mostly free” it was ranked 20th in the world, down three places since last year. The United States has fallen behind countries such as Georgia, United Arab Emirates, and Chile, according to the prominent index. “The major obstacles to greater economic freedom in the United States continue to be excessive government spending, unsustainable levels of debt, and intrusive regulation of the health care and financial sectors,” a Heritage report stated. The Index of Economic Freedom is an annual ranking created in 1995. This year’s index ranks 178 countries by examining qualitative and quantitative factors grouped in four categories—the rule of law, government …