Final answer:
The phrase "the dismal science" is attributed to Thomas Malthus, an English economist known for his theory on population growth and its impact on poverty.
Step-by-step explanation:
The phrase "the dismal science" is attributed to Thomas Malthus. Malthus was an English economist and clergyman who published a book in 1798 titled An Essay on the Principle of Population. In this book, Malthus argued that population growth would inevitably lead to poverty and misery, as the food supply could not keep up with the increasing population. His pessimistic view on the consequences of population growth earned the field of economics the nickname "the dismal science."