Law of Population was a treatise written  as a response to works on population growth by an English cleric and what?
Thomas Robert Malthus Thomas Robert Malthus ( ; 13 February 1766 – 29 December 1834) was an English cleric and scholar, influential in the fields of political economy and demography. Malthus himself used only his middle name, Robert.
Malthusian growth model A Malthusian growth model, sometimes called a simple exponential growth model, is essentially exponential growth based on a constant rate. The model is named after  Thomas Robert Malthus, who wrote "An Essay on the Principle of Population" (1798), one of the earliest and most influential books on population.