Which of the following developments would Malthus have regarded as the strongest evidence that preventive checks were operating successfully?

A decline in birth rates due to delayed marriage and voluntary restraint.

The correct answer is Option 1: A decline in birth rates due to delayed marriage and voluntary restraint.

Malthus distinguished preventive checks from positive checks. Preventive checks involved conscious efforts to reduce population growth, such as postponing marriage or practicing sexual abstinence. A decline in births resulting from such behaviour would therefore be evidence that preventive checks were working.

A sharp rise in mortality caused by epidemics. Incorrect. This is a positive check.

A famine that reduces population pressure on resources. Incorrect. This is also a positive check.

An increase in migration from rural to urban areas. Incorrect. Migration was not identified by Malthus as a preventive check.