The factor differentiates a market economy from that of a planned economy is not on ownership but on the level and extent government meddling into the national economy. In market economy, government manipulates national economy mostly in macro level whereas that of planned ecoonomy will permeate down to micro level. Line is rather blurry nowadays, particularly in comparison between that of China and that of those traditional market economies. Even in a market economy like that of USA, government agencies do sometimes extend their hands into micro level of private companies. It is only matter degree and extent, a quantitative rather than qualitative differences.