Answer:
Free market economies stimulate growth because they give people incentives to become more innovative. In a market economy, people get to keep the money that they make from business ventures (less taxes of course) which spurs them on to compete more and produce better so that they can make more than their competitors and get wealthier.
This competition will stimulate growth and lead to more efficiency because less efficiency means higher costs and less profitability.
This is in contrast to state-directed economies where resources are shared and people have to work for the benefit of others. You will find that those who could have been innovative will lose the urge to be so because they will not get as wealthy from it.
Inefficiency will also be rife as the government tries to include as many people in production as they can which will lead to higher costs and less profits culminating in weak economic growth.
