Final answer:
No country has a pure market or command economy; instead, nearly all countries have mixed economies. The U.S. is more market-oriented, while China and Russia have moved from command to more mixed systems, yet still retain significant government control.
Step-by-step explanation:
There are approximately 196 countries in the world, and each operates under its unique economic system. However, no countries have a purely market or command economic system. Instead, most countries have mixed economies combining elements of both systems, with variations in the degree of government involvement. For instance, the United States leans towards a market-oriented system but still includes some government regulations. Conversely, China and Russia, which previously had strong command economies, have been transitioning towards market-based systems but still retain many elements of government control. The shift from pure economic systems to mixed economies reflects changes in global political and economic landscapes. Historical transitions, such as the fall of communism in Russia and China's market reforms, illustrate how economies evolve over time. These mixed economies seek to balance the tradeoffs between efficiency and equity, as highlighted in economic history and theory.