Walt W. Rostow's 'Stages of Economic Growth' (1960) proposes a linear, five-stage model of economic development that all countries supposedly pass through. The 'Age of High Mass Consumption' is the fifth and final stage in this model, representing the culmination of economic progress.

In this stage, the focus of the economy shifts significantly from basic needs and industrial expansion towards the widespread production and consumption of durable consumer goods and services. Societies reaching this stage are characterized by:

1. High Disposable Income: A large proportion of the population possesses substantial income beyond what is required for basic necessities, allowing for discretionary spending.
2. Mass Production and Consumption: There is widespread availability and purchase of consumer goods such as automobiles, household appliances, electronics, and leisure items. Production is geared towards meeting these diverse consumer demands.
3. Shift in Societal Priorities: The emphasis moves from industrial maturity and power to improving the quality of life and welfare of the population. This often involves increased investment in social services, education, and healthcare.
4. Welfare State Development: Governments often play a larger role in providing social security, welfare programs, and public services to ensure a higher standard of living for their citizens.
5. Technological Maturity: The economy is technologically advanced and capable of innovating and producing a wide array of goods and services efficiently.

Rostow envisioned countries like the United States and Western European nations in the mid-20th century as having entered this stage, where the pursuit of consumer comfort and leisure becomes a dominant societal goal. This stage signifies a mature economy where the challenges of industrialization have largely been overcome, and the benefits of economic growth are widely distributed, leading to a consumer-driven society.