What is the main similarity between Malthus and Ehrlich?

The answer is correct because both Malthus and Ehrlich shared a fundamental concern regarding population growth and its potential consequences. Thomas Malthus, in the late 18th century, famously argued that population growth would outpace food production, leading to inevitable famine and hardship. Paul Ehrlich, in the 20th century, echoed this sentiment in his book "The Population Bomb," where he warned about overpopulation leading to resource depletion, environmental degradation, and societal collapse.

Despite the differences in the time periods and contexts of their work, the core similarity lies in their view that unchecked population growth poses significant risks to societal well-being and environmental sustainability. While their proposed solutions and specific concerns diverged, the underlying premise regarding the dangers of population growth connects both thinkers.