Malthus was absolutely correct. When he wrote, societies had been for millenia going thru cycles of population growth, which then bumped up against the limitations of the system for producing food and other necessities. Not surprisingly, the Malthusian dilemma contributed to political unrest and the rise of "reformers" who generally made things worse. This would be followed by the population dropping as a result of the Four Horsemen. For example, most changes of dynasty in China resulted in a 40 to 70% drop in the population. And the cycle begins again.
Malthus did not recognize the impact the Industrial Revolution, in full swing during his life, would have on wealth and food production. He, along with just about everybody else, also did not expect that people would begin voluntarily having fewer children as their standard of living improved and fewer of their children died.
These two facts, with others, have removed us from the Malthusian dilemma. So far. But in a "state of nature" it absolutely exists. Human population has the potential to grow exponentially. Given muscle and wind power technology, food production can only grow arithmetically. Malthus wins every time.
All of the historical evidence both before Malthus and available to him, and afterward, is unanimous, that population growth *increases* per capita productivity, and does not decrease it. All of the periods of declining per capital income in collapsing empires, are periods of declining population as well. Nowhere is the association of population decline with *rising* productivity, that Malthus postulated, seen *anywhere* in the historical record, premodern or modern.
It was and it is simply a mistake. It is a failure of accounting. The true relation is dirt simple, stated in value terms.
In free exchange relations, men will not award to any worker or earner more than the real value of his production to others, as his share of his own product. Otherwise put, free entrepeneurs or employers do not continually employ others to produce at an ongoing loss, in value terms.
Anyone taking less in value terms from the total value produced, than he himself contribute to that total, necessary is *not* a net drag on the total surplus value available to everyone else. Otherwise put, *every* worker under conditions of free exchange, profitably employed, produces *positive* and not negative, externalities to everyone else.
The *only* way this relationship can be broken, is for men to be continually employed in processes that *destroy value*, and that award them *far more* than the real value of their productive efforts, to others. The *leading cause* of such breakages in human history, have been extractive bureaucracies that employ large numbers of functionaries in politics and extraction itself, and that subsidize political support from unproductive citizens (the classic term is "drones") at the expense of actual producers.
In the absence of such distortions of free exchange and profitable employment, men *pay for themselves* and their own support, in the value they produce. Necessarily. They are therefore incapable of extracting more than they produce in value from others, and therefore are incapable of causing large net negative externalities to everyone else. That is *why* population *increase* under conditions of free economic exchange are *always and everywhere* accompanied by *increased* per capita incomes and not the reverse. And conversely, why overgrown extractive systems that deliberately short-circuit this relationship through redistribution, *always and everywhere* soon result in *declining population*, and with it *economic decline*.
Freedom prosperity and population go hand in hand. Statism destitution and depopulation go hand in hand. Malthus has the sign of the association wrong, as well as misunderstanding its logic.
At bottom, the reason Malthus made this error is that he lacked the marginal theory of value, and with it the law of the distribution of factor returns under conditions of free exchange. Without that understanding, he had only the old association of *commodity prices* with their *cost of production* as a theory to predict the equilibrium level of prices. He then applied that notion to *labor* and to *capital*, but inconsistently *failed* to apply it to land. This led to his prediction that in equilibrium, *all* surplus value would fall to *land rent* as its income share, with capital earning only enough to replace itself (profitless depreciation coverage only), and labor earning only subsistence wages.
Needless to say, this prediction was false the day it was written, and has never been observed in practice, to the slightest degree, in any society. All surplus does not fall to land rent, and there is nothing magically scarce about land, only, as Malthus thought. Land, labor, and capital all earn out of their joint product according to their *marginal productivities*, as incremental inputs to the production function, at any given technological level. When the true value of labor rises, so does the *real wage* of labor, and is proportion of the total income.
The true law of marginal productivity was first seen by Malthus' contemporary Ricardo, and formed a key point in their debates in his own day. But Ricardo did not succeed in elaborating the true doctrine of marginal productivities and its role in factor incomes, in his own day. The details were only fully understood later in the 19th century, when the theory of income from capital was finally put on a sound footing. That required understanding the phenomenon of time-value, of which both Malthus and Ricardo were completely ignorant.
Despite originating in economics and being known to be a fundamental error in that sphere, by later in the 19th century, Malthusian ideas neverthless survived, in part because the socialist doctrine had grown up in the meantime around the putative "iron law of wages" and the prediction of subsistence as the equilibrium level of the income of labor; and also because in the meantime, Malthusian ideas were exported from econ to biology, via Darwin. This allowed them to be reimported continually without their economic errors being acknowledged, with an air of greater scientific legitimacy than they merit without econ itself.
All sound economists know this history, and understand that Malthus was utterly wrong. Nearly every modern political ideology, however - except libertarianism of the Austrian variety, to be fair - has remained infected with Malthusian nonsense. It remains *nonsense*, and false.