{"id":81,"date":"2004-07-02T11:49:44","date_gmt":"2004-07-02T16:49:44","guid":{"rendered":"http:\/\/server97.snhdns.com\/~ravik\/wp\/?p=81"},"modified":"2004-07-02T11:49:44","modified_gmt":"2004-07-02T16:49:44","slug":"what-was-malthus-thinking","status":"publish","type":"post","link":"https:\/\/www.ravikiran.com\/blog\/classic\/200407\/what-was-malthus-thinking\/","title":{"rendered":"What was Malthus thinking?"},"content":{"rendered":"

I love it when my readers do my hard work for me. I am talking, of course, of Mayank’s <\/a> comment to my Genghis Khan post. I am reproducing the comment here, with only cosmetic changes. He has done half my work for me. <\/p>\n

I did a brief mathematical analysis of this claim. There were around 40 crore people in 1250(source<\/a> ), after Genghis Khan’s tenure compared to 600 crore people now. So, a simple back-mapping tells us that 1.6 crore men now, will have approximately 10 lakh ancestor males in that population, the assumption being here that the children Genghis khan spawned were not in general more promiscuous than the other contemporary adults<\/b>. So, this brings us down to account for 10 lakh people with the same Y chromosomes as an immediate result of the sexual excesses of Genghis Khan, his four sons and two grandsons as mentioned in the article. The fact that only Genghis khan is remembered for those brutalities means we can safely assign half of that figure directly to him.
\nThis means one king in 40 years actually spreads his Y chromosome in 5 lakh males. With 40 years meaning arnd 15k days, he actually succeeded in impregnating 33 women per night( or day too, if he had no other job ).
\nThe fallacies in the above simplistic assumptions are not hard to find. We can easily say that the tribes originating from him gave birth to more children etc. But that doesnt make the scenario look any more feasible. Well if he did…. HATS OFF TO HIS STAMINA AND LUCK.\n<\/p><\/blockquote>\n


\nSo as I was saying Mayank has done half<\/i> my work for me. One mistake in his calculations is that if you assume that Genghis Khan had 5 lakh sons, statistically you must also assume that he had as many daughters (unless he practised some kind of sex selection.) And of course, not all sexual encounters result in children, so we may have to scale up the figure of 33 that he got by some factor. That of course, makes the figure even more implausible. <\/p>\n

The other assumption (which I have bolded) is actually wrong. If you follow the link to Kuro5hin that Ravages posted (in the same thread), you will realise that Genghis’ progeny were part of ruling clans in Mongolia till as late as the twentieth century, so we can safely assume that they were in general more promiscuous than other contemporary adults. <\/p>\n

Does this mean that Mayank is wrong when he says that the scenario won’t look any more plausible if a few of his assumptions are wrong? Let’s see.<\/p>\n

There is another way to verify the answer. Look at it this way. Consider a normal woman. How many children would be born<\/i> to her if she didn’t use contraception? 10? I think 10 sounds plausible. Statistically, of them, 5 would be boys. And how many generations would be there between AD 1250 and AD 2000? Let’s assume that the average gap between generations is 25 years. So we can safely assume 30<\/a> generations.
\nHow many male progeny will an average man have if we assume that all his 5 sons succeed in having their quota of 5 sons each generation after generation? Well, you won’t believe the answer. It is 9.31322575 \u00d7 10^20<\/a>! <\/p>\n

So Genghis Khan would not<\/i> have to be particularly promiscuous to ensure that his male descendents numbered 16 million 800 years down the line. He’d just have to ensure that his descendents survived<\/i> at a rate better than the rest of the population. Partly he managed to do this by having a lot of children and relying on the law of probability. The other part of his trick was that because his descendents were part of ruling clans for an awfully long period, they survived at a rate much higher than the general populace.<\/p>\n

But this post isn’t about Genghis Khan. It is about Malthus. So let’s ask another question. If 10 children is a reasonable guess and all ten children survive generation after generation, we’d have ended with that unimaginably huge number right? But the world population did not<\/i> increase by that unimaginably huge figure. It increased only 15 times. So the question is, how many of your children, on an average<\/i> must go on to have children for the population to go up 15 times over the period of 750 years? Assuming 30 generations as before, the number we’re looking for is 1.09<\/a><\/p>\n

Hold that figure in your mind. Of ten children that an average couple had, two<\/i> went on to have children of their own. One fifth.<\/i> <\/p>\n

What happened to the rest? Did they decide to stay celibate and hence childless all their lives? Unlikely. If celibacy was so widespread in medieval times, we would have heard of the phenomenon. No that can’t be the explanation, and you won’t like the real explanation. They were dying<\/i>. The lucky ones, 2 out of the ten, used to die as infants. Others must have fallen victim to the horsemen of the apocalypse – disease, war, pestilence, etc. <\/p>\n

And also remember that the population rise by a factor of 15, which we think of as meteoric*, but it actually isn’t, really started with the onset of the industrial revolution. Before that the population used to be static over the long term. As we have seen a “static” population actually means that four-fifths of the population on an average used to die before old age. “On an average” means that sometimes things were better and sometimes they were worse.<\/i> When they were worse, entire populations must have been wiped out in massacres, plagues, famines, etc, as happened in Europe during the plague. <\/p>\n

I am not given to hyperbole (I haven’t read the One Book That Cannot Be Named written by The Verbal Terrorist yet), but I hope that I have made the point that things used to be horrible in the past. I can’t even imagine what kind of life it would be where you could expect to see most of your children die young. <\/p>\n

The other point I want to make is that population growth is a result of prosperity<\/i>, not a cause of poverty. So when Malthus was claiming that if population grew too much we’d end up with famine, starvation and disease, he wasn’t predicting the future. He was describing the past and there too he got the cause and effect wrong. The wars, droughts and diseases weren’t occurring because of overpopulation. They were always there, though they did end up “controlling the population” <\/p>\n

Now I am not claiming that we can never be overpopulated. I am only saying that overpopulation is a far better problem to have to solve than the alternative. <\/p>\n

*I don’t know why a rise is called meteoric when a meteor actually falls.<\/small><\/p>\n","protected":false},"excerpt":{"rendered":"

I love it when my readers do my hard work for me. I am talking, of course, of Mayank’s comment to my Genghis Khan post. I am reproducing the comment here, with only cosmetic changes. He has done half my work for me. I did a brief mathematical analysis of this claim. There were around […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"","sticky":false,"template":"","format":"standard","meta":[],"categories":[2],"tags":[],"_links":{"self":[{"href":"https:\/\/www.ravikiran.com\/blog\/wp-json\/wp\/v2\/posts\/81"}],"collection":[{"href":"https:\/\/www.ravikiran.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.ravikiran.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.ravikiran.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.ravikiran.com\/blog\/wp-json\/wp\/v2\/comments?post=81"}],"version-history":[{"count":0,"href":"https:\/\/www.ravikiran.com\/blog\/wp-json\/wp\/v2\/posts\/81\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.ravikiran.com\/blog\/wp-json\/wp\/v2\/media?parent=81"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ravikiran.com\/blog\/wp-json\/wp\/v2\/categories?post=81"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ravikiran.com\/blog\/wp-json\/wp\/v2\/tags?post=81"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}