Thomas Malthus, the Doomsdayer

At the close of the 18th century, England's food prices were high and population growth was unrelenting, putting pressure on the food supply. There was a recent "apparent" increase in poverty(difficult to verify; perhaps migration from rural areas to urban areas simply made poverty more visible). Utopians asserted that social and political institutions were the cause of poverty and misery and therefore, changes in those institutions could eliminate the resulting evils.

And along comes Thomas Robert Malthus to refute the Utopian beliefs with systematic population studies in his "Essay on the Principle of Population as It Affects the Future Improvement of Society"(1798). His primary thesis was that population tends to increase faster than the food supply. He found that the food supply increased at an arithmetic rate, while the population increases at a geometric rate. There existed, however, some checks to the population. Some are positive population checks, which is to say they increase the mortality rate. These include disease, war, and famine. On the other hand, preventive population checks decrease the fertility rate: moral restraint and vice. Vice, in this instance, refers to birth control and prostitution. Malthus' analysis had flaws: he underestimated the growth of productivity in agriculture and he failed to predict the birth rate would decrease as a result of urbanization, higher incomes, increased education of women, and more modern methods of birth control.

One of Malthus' assertions was that real wages would tend toward subsistence level. Higher incomes (when wages were above subsistence level) lead to a higher fertility rate and by consequence, a larger population, bringing the wage down once again to subsistence level. 

Malthus took a strong stance on England's Poor Laws, claiming that any social welfare program was counterproductive because it would increase the population without also increasing the food supply.

Malthus also developed a theory: the Underconsumptionist theory. He explained that excessive saving and insufficient consumption had created a lack of aggregate demand. His solution, therefore, was unproductive consumption. Unproductive consumers included landlords and those who provide services-these individuals had the capacity to consume without producing and thus, save the economy.

The work and ideas of the father of demography and population studies, Thomas Malthus, continue to affect modern debates on population growth and utilization of resources.