Final answer:
According to Walt Rostow, the final stage of economic development is the age of high mass consumption.
Step-by-step explanation:
According to Walt Rostow's model of economic development, the final stage is the age of high mass consumption. This is when a society has reached a level of economic growth where most of the population is engaged in a consumer economy, with small family sizes and high incomes. In this stage, technology is advanced, and citizens enjoy a higher standard of living.