5 ms·

Malthus introduced exponential growth rates, but not equilibria; he assumed a runaway growth would lead to collapse. Logistic functions, which describe equilibr

• SiVal 14y ago
  I agree that these aren't Malthusian, and some aren't even true. The ones that are true seem to exemplify incentives and constraints. When you have an incentive to do more, you do more until either the incentive (marginal_benefit - marginal_cost) or your ability to do a little more fades to zero. When the incentives or constraints change, the behavior adapts accordingly. A Malthusian collapse is a special case that is not relevant to most situations of incentives and constraints.
  • CWuestefeld 14y ago
    But the reason that Malthus' doom-mongering hasn't come to pass is because he failed to consider that there was sufficient incentive for people to find alternatives, such that they could skirt the constraints. Malthus said that the carrying capacity of Earth is limited to X because of finite arable land (and so on). But then humans came up with irrigation, and crop rotation, and terracing, and selective breeding, and fertilizers and insecticides, and powered machinery, etc., all of which allowed the Earth to provide for ever-increasing numbers of people. Malthus saw humanity as limited to subsistence dirt farming, but the people saw the ability to prosper, have large families, etc., as sufficient incentive to invent alternatives. The incentives didn't change, and the constraints only changed so far as did the body of human knowledge.
    • slowpoke 14y ago
      It is true, though, that there is a limit to how much people this planet can reasonably sustain, and I'd say we're billions over that mark - the only reason the system still works (barely) is because a large part of the world's population lives in poverty and hunger. Optimization will only get you so far. We simply can't optimize away the fact that there is limited space on this planet and that we're pretty much out of it already. We can't sustain 7 billion people, tendency growing. Not at a humane average living standard.
      • kbolino 14y ago
        I don't think you deserve the downvotes; your point may be valid, even if pessimistic. Just because we've managed to overcome what seemed to be infeasible hurdles doesn't mean we will continue to do so. Of course, just because the new hurdles seem even less feasible doesn't mean we won't overcome them, either. The point being that you'll never know you're at the cusp until you're well into the valley on the other side. Malthus was wrong about the long-run behavior of populations, but I think it's worthwhile to note that we can feed yesterday's population today. World hunger could have been a solved problem with all the advances that were made. But who has the right to tell you not to breed?
        • CWuestefeld 14y ago
          Well, the argument needed to be made because there are so many who subscribe to it. But the important point that this misses is that the availability of any given resource isn't what's critical, since all throughout history it's been shown that human ingenuity has been able to find alternatives. The critical factor is that human ingenuity. And because that human factor -- the availability of someone who can figure out that alternative, and who has the incentive to do so -- is growing with the growth of the population, are horizons are only broadening! Contrary to Malthus, an increasing population is, in the long run, better for mankind's prospects.
          • _delirium 14y ago
• rsheridan6 14y ago
  >Malthus introduced exponential growth rates, but not equilibria; he assumed a runaway growth would lead to collapse. Malthus said population growth exceeds the potential for food supply growth, which is compatible with either a collapse or logistic growth.