Step 1: Understanding the Concept:
The question describes a foundational theory in demography and economics regarding the relationship between population growth and resource availability.
Step 3: Detailed Explanation:
This theory was proposed by the English economist Thomas Robert Malthus in his 1798 work, "An Essay on the Principle of Population". The core idea, known as the Malthusian Theory of Population, is:
\[\begin{array}{rl} \bullet & \text{Population Growth: When unchecked, population tends to grow at a geometric rate (e.g., 2, 4, 8, 16, 32...).} \\ \bullet & \text{Resource Growth: The food supply and other resources tend to increase at a slower, arithmetic rate (e.g., 1, 2, 3, 4, 5...).} \\ \end{array}\]
Malthus argued that this disparity would inevitably lead to a point of crisis (a "Malthusian catastrophe") where population outstrips resources, leading to famine, disease, and war.
Step 4: Final Answer:
The theory was given by T. R. Malthus.