Final answer:
Communism is the most rigid and least responsive economic system with very little incentive for people. It is a command economy with centralized control and lacks the adaptive qualities found in capitalism and mixed economies.
Step-by-step explanation:
The economic system that is typically viewed as the most rigid and least responsive to change, offering the least incentives for people, is communism. Unlike capitalism or a mixed economy that encourages market-driven innovation and competitive efforts, communism, being a command economy, has all economic decisions made by a central authority with little to no input from individual actors. Resource and production decisions are planned and mandated by the government, and the absence of private property or profit motive significantly reduces the incentives for innovation and personal economic advancement. This often results in less agility and slower response to changing economic conditions and consumer preferences.
Communism functions both as an economic and political system, which further entrenches its rigidity by concentrating power within the state apparatus. In contrast, the competition inherent in capitalism and the flexibility of mixed economies provide more adaptive frameworks that can shift according to societal needs and technological changes.