Tuesday, February 10, 2015

Fantasy and the Malthusian Trap

We all know that most fantasy stories aren't especially realistic. The real world is notably lacking in dragons, orcs, wizards and meddling gods, all of which are staples of the genre. Of course, those are all intentional bits of unrealism created to allow us to tell stories that couldn't have happened in Earth’s real history. But there’s a more subtle sort of unrealism that pervades the field, invisibly undermining the verisimilitude of otherwise well-written stories and bleeding incoherence into their deeper themes.

One common example of this is the issue of the Malthusian trap, or rather the fact that virtually all pre-industrial societies that practiced agriculture spent their entire history caught in it. This is something that experts have only really come to appreciate in the last few decades, and the implications don’t seem to have spread to the general public.

Briefly, the ‘Malthusian trap’ is the fact that in pre-industrial societies population growth happens faster than any feasible increase in food production. It takes years to build irrigation systems or terrace hillsides, and generations to get illiterate peasants to adopt a new farming technology. But the gains from such changes are relatively modest, and a population of poor farmers will grow quite rapidly if they actually have enough to eat. So the result is that once a society discovers agriculture it quickly spreads until all the land in the region that can be farmed with its current technology is under cultivation, and then the population continues to grow until starvation becomes common enough to keep it in check.

Let’s stop and think about that for a minute. We’re talking about civilizations where 95%+ of the population are illiterate farmers with no access to birth control. That’s a lot of starvation. By modern standards it’s an almost unimaginably brutal world. But this single realization explains countless examples of ancient behavior that would otherwise be inexplicable, while also closing off almost every way of improving the situation.

Why was life so cheap? Because even in a normal year there are people starving to death in every village in the country. So if someone dies working in the mines or fighting enemies on the frontier, that just means there’s now enough food for someone who was going to starve to death to live.

Why did legal codes make such free use of the death penalty? Because every criminal you kill is another honest citizen who gets to live. If you lock a criminal in prison and feed him you’re taking that food from the mouth of a needy peasant somewhere.

Why was infanticide so common? Because peasants didn't have birth control, and it was commonplace to find yourself with more children than food. Leaving an infant on some hillside wasn't easy, but it was better than keeping the baby and killing one of your older kids instead.

Why were sons more prized than daughters? Well, ok, there are several factors at work there. But a major one is the simple fact that the average woman eats 70-80% as much as a man but has barely half the upper body strength, and on a farm that modest loss of efficiency could often mean the difference between survival and starvation.

Why didn’t benevolent rulers use their great wealth to help their people? Because it doesn't work. Lowering taxes and helping the needy means fewer people will starve this year, but that just allows the population to grow. Keep it up for a few years and the population will expand until it overwhelms your resources, at which point the peasants will be back to living on the edge of starvation. At which point they’ll probably blame you for the change, and revolt.

All of this is important for fantasy writers, because it implies that the happy bucolic prosperity you see in so many recent stories is simply impossible. If the peasants of Happyville have warm, comfortable houses and plenty of good food that means every family is going to have half a dozen kids. A generation later you’ll have a lot more people trying to live on the same land, and everyone will be too busy trying to squeeze a few extra cabbages out of marginal bits of land to build nice houses or other creature comforts.

Having a few wizards wandering around doing small-scale magic on occasion doesn't change this brutal math, and even the wisest of immortal rulers will find no policy they can enact to change things. A strong government can to some extent decide who lives and who dies, by collecting taxes (usually as food) and distributing it to favored groups. But the population is going to grow until something stops it.

Now, there is one way to have a pre-industrial society where the commoners are prosperous, but it isn't much of an improvement. If something kills off a decent fraction of the population every few years that might be enough to arrest population growth before you get to the stage of constant near-universal hunger. But keep in mind that you have to kill women and children too, not just the men. A society can have a third of the men die in some distant war every generation with no effect at all on population growth - what matters is how many of the women survive to have children.

So how did we get out of this trap in the real world, if it’s such an iron law?

That’s an interesting question, but historians and economists can’t quite agree on an answer. The first part is clear enough - industrialization kicked off an era in which food production, transportation and storage all improved much faster than was previously possible, and actually got ahead of population growth for several generations. But after that some combination of social factors caused people in developed nations to start having fewer and fewer children, making it progressively easier for food production to stay ahead of demand. At this point people in developed nations have so few children that populations are actually shrinking, although the availability of reliable birth control for the last 40-50 years may have something to do with that.

What this all means for fantasy authors is that if you want to write realistic stories you only have a few choices. You can introduce industrial-scale magic that transforms society into something resembling modern-day Earth, but then you’ll end up with a story that looks more like SF than fantasy. You can impose some kind of universal birth control system far more effective than anything that has ever existed in the real world, but then the societal effects of that regime are inevitably going to dominate your story. Or you can pick a familiar medieval or ancient setting, and accept the fact that you’re writing about an incredibly brutal world where mass starvation is a daily fact of life.

...or you can retreat into urban fantasy, and spend your time writing about some Strong Independent WomanTM and her struggle to decide which sexy half-human alpha male she’s going to date. But that’s not the kind of story I’m ever likely to ever write.


  1. The bit about son over daughter births is rooted in farming power is new to me. What is the evidence that for that assertion?

    1. China. Throughout the entire history of the country up till right now, and continuing.

    2. Which part do you want evidence for? That people in primitive societies often have a preference for male children? That men are substantially stronger than women? That low-tech farming is a backbreaking enterprise where physical strength has a substantial effect on work output?

      Those all seem like well-documented facts to me, although as I said there's usually a lot of other factors involved in the evolution of cultural preferences.

    3. No, I interpreted what you said is that the need for strength in farming is a leading cause of male selection / preference. But, it seems odd because it I can only imagine it applying the need to plow. However, harvesting & hunting would be easily done by women. In fact my understanding is that many women did work the fields.

  2. Solving food shortages is a little outside the main MC and his party's field of expertise. Unless he makes giant regenerating magic cows immune to the cold? Didn't Thor have something like that with his goats? Immortal edible transportation.

    1. Avila, as a hearth witch, would be exceptionally well suited to fixing the problem, given the right resources. She can make things grow like crazy in her own garden, right? So if she gets a country of her own (or if Daniel does), the fields of that country, by extension, become her property, and she can bless them with bountiful harvest.
      Similarly, given enough power, she might be able to formulate a country-wide fertility curse to make sure each woman can only have three living children at the same time.

      Though above reasoning is pretty much moot because with eternal winter and monsters everywhere, the population should drop pretty fast regardless...
      Yeah, Sæhrímnir-style regenerating livestock might be the way to go; way easier to defend than grain fields that have to be guarded for months at a time.

  3. This is an interesting assertion, but I'm not fully convinced. It's certainly true that Medieval Europe had a lot of issues with famine, so if you're writing a fantasy story that very closely hews to that paradigm then food issues are probably relevant to your story (you're exclusively writing from the perspectives of nobles who don't actually care what's happening in the kingdom).

    On the other hand, there have been plenty of pre-modern ages and social systems where famine was NOT a constant part of life, with China being an especially important example (pre-decline Rome too, though I'd say to a lesser extent).

    So I'd say that Malthusian resource issues are probably relevant to a story unless the birth rates are kept under control, with meausres such as:

    - Birth control (potentially up to and including abortion) is fashionable instead of essentially banned by religion;

    - You have a relatively stable society, and wars and diseases are relatively uncommon instead of constant, so the population naturally keeps closer to some kind of equilibrium level, instead of massive booms to make up for the frequent busts of war/disease;

    - You have a slave/serf society where slave/serf birth rates are forcibly kept low;

    - Peasantry have relatively strong property rights (Rome is a reasonable example of this, since they basically gave land to soldiers who conquered it for the empire)

    - You have a wide-spread bureacracy that keeps on top of how society is functioning (China is a good example of this, though here it's probably more managing food supply than directly forcing birth rates down)

    So while you definitely can write a fantasy story where Malthusian issues are relevant, you can also write one where it isn't very relevant. You just have to make sure it takes place in a relatively functional, stable, organized and peaceful society. i.e. the opposite of Medieval Europe.

    PS You can also sort of get away with ignoring this if you're exclusively writing from the perspectives of nobles who don't actually care what's happening to common people (GRRM in ASoIAF does this effectively - it's known that life really sucks but his characters aren't the sort of people who care about the details)

    1. I can't imagine why you think famines were limited to Europe. Every pre-industrial society that practiced large-scale agriculture was subject to regular famines, and reams of academic papers have been written about their effect on the religion and culture of every major state from Spain to Japan. Periodic famines are a natural side effect of the fact that climate fluctuations cause substantial variations in crop yields from one year to the next, and low-tech societies have no way to preserve large quantities of food for long periods of time.

      But even that is missing the point, which is that even in normal years a small but significant fraction of the population is always starving. While boom/bust cycles can happen, even without them the population will naturally grow until food shortages become severe enough to stabilize the numbers. This is actually well attested in ancient literature, where starving poor people are always part of the scenery and even the most benevolent writers generally assume there's nothing to be done about them.

      But don't take my word for it. Google it, and check out the academic literature on the subject.

  4. Figuring out the economics of a fantasy world is a necessary step to having a world that is consistent. I might quibble about the marginal returns on peasant labor but the important part is that the world of Fimbulwinter has to deal with scarcity and labor that is not very efficient. My understanding is that even with low levels of technology - or perhaps because of low levels of technology a functional adult generated more than they needed to consume. I am not sure that surplus labor was the big hurdle back in the day. One of the tough things was infant mortality and childhood mortality and generally low life expectancy. A person takes a lot of labor to raise till they become useful and often in earlier times that investment didn't pay off. People died before they were able to contribute more than they took raising them. In that sense Daniel's capabilities and perhaps in upcoming books Avilla's powers will be hugely valuable. Avilla can provide the things like sanitation - the single greatest boon to life expectancy and productivity we have ever developed. Sick people and dead people produce nothing. Effective sanitation saves more lives than al the drugs and anti-biotics we have ever developed. Certainly Avila can keep more people alive than Daniel can healing them one by one.

    Knowing the economic and technological truth of the past is no more certain than knowing how these things work in the modern world. What is appreciated is when an author attempts to keep their world grounded and consistent. Most of the middle to high brow Sci Fi/Fantasy uses this to make social commentary. I usually get irked with this as the social or historical insight isn't that deep or interesting and is often at the expense of a tight narrative. Even worse is when an author tweaks some aspect of how the world works in order to make a heavy handed political point yet allows inconsistencies in the world building if it gets in the way of their message.

    This is all very interesting but GET BACK TO WORK! FINISH BOOK TWO!

    1. > My understanding is that even with low levels of technology - or perhaps
      > because of low levels of technology a functional adult generated more than
      > they needed to consume.

      One needs to differentiate by time, locality and even season. A a lot. Mr. Brown puts his finger squarely on a problem afflicting a lot of genre literature (or for that matter fiction in general) in his article. Unfortunately the point he's making gets undermined by at least partially basing his argument on a few common 'dung ages' misconceptions.

      I know i'm a pedantic twit with way too much utterly-irrelevant-to-real-life historical data stored in my brain, and the fact that he considers such things in his writing at all puts him well ahead of most (though not all) the authorial pack, but i'm afraid a good number of the things he brings up are if not outright false so framed in hyperbole as to be 'not even wrong'.

      > One of the tough things was infant mortality and childhood mortality and
      > generally low life expectancy.

      There are a lot of misconceptions about medieval and early-modern demographics and standards of living. To begin with, the 'average' life expectancy is meaningless. Generally, about 1/3-1/2 of people born died before age 20. This is the biggest single difference between now and then.

      If you lived to be 20, you would probably live to 60 or so, unless you were in a bad environment like a big city.

      Reproduction: Puberty for women came about 2-3 years later than with us (mid-teens, usually) and menopause usually a couple of years earlier.

      _Married_ women generally had a pregnancy every 2-3 years until natural infertility set in.

      Since the age of marriage was around 25-26 usually (about 10 years after puberty), and natural fertility drops off very sharply from the mid-30's on, the typical married woman had 4-6 pregnancies (It was quite rare for unmarried women to get pregnant, and even rarer for the child to survive, unless the father was a wealthy man prepared to support it.)

      Keep in mind that 's the average; some had 10 or more children, some 1 or none. 4-6 would be regarded as "normal" at the time. Of those 2 or 3 would survive to adulthood.

      And a _lot_ of women never married and in that case generally died childless and (at least technically) virgins. Never less than 5%, sometimes as many as 25%, and averaging a bit over 10% century to century.

      Diet and standard of living: This varied very, very widely from time to time and place to place.

      The best way to determine nutritional status is by average heights. For most of the medieval period, the average height was 1-2 inches below mid-20th century levels. For example men in England generally were about 5ft 7 inches and women about 3-4 inches smaller.

      In other words, they weren't as well fed as we are, but they were usually about as well-fed as our parents or grandparents. Add in that disease and very hard work eat up a lot of your food energy, which means they were eating better than you'd expect just from the height measurements.

      There were periods of widespread malnutrition - the late 13th and early 14th centuries, for example (*). Conversely in the period after the Black Death, food was very cheap and most people ate a lot of high-energy foods like meat.

      The early modern period was one of regression in nutritional standards, people got shorter, except in America and other colonial frontiers, where they achieved modern heights as long ago as the early 1700's.


      * = but even for those periods to claim that “in a normal year there are people starving to death in every village in the country” is, and i'm sorry to say this, complete nonsense.

    2. > A person takes a lot of labor to raise till they become useful and often in earlier times that
      > investment didn't pay off.

      We've actually got pretty good data on the 'return of investment' for rural children raised in a pre-industrial environment thanks to the surviving financial records of slaveholders in the Americas.

      There are of course local factors that can skew things one way or the other within certain limits, but a fairly firm rule of thumb was that as a parent/owner you didn't break even on a child/slave's labor until they turned about fourteen, and didn't start to make a profit until sixteen and up, with peak productivity in the 20s and 30s.

      > My understanding is that even with low levels of technology - or perhaps
      > because of low levels of technology a functional adult generated more than
      > they needed to consume.

      Yes/No/Sort of. The first bottleneck in wheat yields is soil nitrogen, followed by things like phosphorus, assuming that there's enough (but not too much ) water in the right places.

      Medieval yields were very low (8-12 bushels per acre) due mainly to nitrogen shortage. The "agricultural revolution" of the 17th-18th centuries broke the nitrogen shortage by introducing a leguminous, nitrogen-fixing crop like clover or alfalfa into the standard rotation, and also by growing other fodder crops (turnips were a classic) which increased the livestock and hence manure for the grain fields.

      That arrangement required either naturally neutral-to-slightly-alkaline soils or extensive treatment with lime to correct soil acidity; legumes are picky about that.

      On good land like, for comparison, the Willamette valley (which has just about a perfect winter-wheat climate of mild wet winters and warm dry summers) you could expect to get 30-40 bushels an acre of wheat, using say a 4 or 5-year rotation; something like:

      1st year - wheat, planted in November, harvested in June-July.

      2nd year - wheat or barley or oats, undersown with a clover/alfalfa/grass pasture mix.

      3rd year - pasture and possibly some hay (the Willamette has a long growing season).

      4th year - pasture and hay

      5th year - fodder crop (turnips, field beets) heavily manured, or sometimes potatoes instead.

      That would give you a good grain yield in the 30-40 bushel per acre range, or even more, plus a lot of fodder so you could support livestock, plus turnips and potatoes, and it would maintain the fertility of the land nicely.

      Ten acres on that rotation plus a couple for permanent pasture, orchards and truck gardens would support a family of five.

      Please note that -none- of this requires tools or skills that hadn't been readily available in the 12th century, or for that matter in the 12th century BC. The reason the agricultural revolution didn't happen five-hundred years earlier was legal not technological in nature.

    3. Your post about death rates and life expectancy and diet paints a different picture.

      I'd imagine life being thought of as more sacred in these circumstances (I know, massive assumptions based on my own mind-set but I did say 'imagine' :P )

      I say this because if death rates pre-adulthood were higher than once you reached adulthood and this was also where people were least productive, then once they became an adult they represented an investment that was currently paying off, hence valuable!

      Of course it also makes the death penalty sensible because if they're an investment that's not paying off, cut your losses. (Unless you have a way to force them to pay off, like slavery I guess?)

      Much food for thought (aha I'm so witty), appreciate the info!

  5. Yeah he missed overpopulation growth causing mass epidemics that killed off the populations of the day. Also anti-polygamy measures might have their root in population control. I.e. losing a third of the men in the country to war caused required that that third of the female population without men to die off from mass starvation in following years order to keep population levels steady generation to generation and open up new fields for those families whose males survived the wars, plagues and unlucky famine years.

    They've also done back to farming reality shows and except for the big and brawny women who can spell their husbands half and half, the best most women could do plowing a field was a couple hours at best, with the smaller women not even able to do that. Versus the husbands who bitched and complained with the whiners doing about 6 hours and the majority pulling 8-12 hour days depending on planting needs.

    In non-tropical temperate areas you have an increasingly smaller planting window to get the sod busted and seeds spread into the ground. So the ability to pull those 12 hour days of hard labor were critical especially the further north you went. Meaning you might have a 6-8 week window in a hotter climate (where lack of rainfall caused mass famine) to a more modest 3-5 week window in more sub-arctic areas like norway/sweeden. With variations in between. Meaning a woman who could only do half the labor of a man could only plant half the fields. Plus all her home maintenance and cooking duties fell fallow unless she had kids old enough to pick up the slack. Also with her out working the fields, the traditional female worked small gardening plot for herbs, non-storable vegetables and other vitamen and mineral supplementing food types wouldn't be worked. Most farms did lots of wheat or barley or other highly storable food types that could travel easily and thus be used to pay taxes as well as keep through the winter (remember they could make saurcraut cause its just open top fermenting but they had little to no canning ability to keep vitamin supplumenting foods through the winter) so a one woman lead household had to pray she was a traditionally oversized woman capable to doing 80+% of the man's traditional field duties but also have children old enough to keep up the garden plot so that they didn't have major mineral and vitamin deficiencies and have their teeth fall out during the winter.

    Which of course ignores the unpleasant local and kingdom level realities. I.e. a woman run household is not only short one adult laborer but for means of protection for things such as raids and rapes and slave taking and such they are down their best fighters. I believe they've shown that it takes olympic class female swordsmen to take on professional level swordsmen and they don't always win. So without magic, while women 'can' go toe to toe with the men, if they're spending all their time in the fields instead of rising to olympic quality sword levels, then when the local man-at-arms comes riding bye she's up a creek if he's not feeling all nice and civilized about things in this plague ridden, muscle powered, starvation prone society.

    The Deposed King

  6. I'm just saying if your worried about the food problem in the story I personally always thought they would eat their Enemies like the Felwolves or with his flesh magic he could cut off a leg of a wolf and heal it then Rinse and repeat but also if i'm not mistaken he could create people or atleast Creatures animals it seems completely Feasible to me with he powers and his basic understanding of biology and the human cells, working nerve ending etc and then create a "Device" or "Artifact" what ever you want to call it to make sure the creature heals so they can Farm meat from it preferably meat from a area of the body that doesn't technically matter like a leg or some appendage or part of the body without any major organs Etc but these are just my personal ideas and thoughts but i'm more worried about the items Avrille needs like Honey and the spices yeah she could grow them if she ever gets her own garden honey would be harder to find but still those are the only things i can thing of i've been wondering how your going to keep them feed the whole time but i'll have to wait XD Keep up the amazing work

  7. One thing is that if magic is common in the sociaty you will have changes bacause of that one of those would probobly be birth controll of some fashion ( a potion, spell or something) that you can make work better then it does in the modern world for example a dual potion take the first one when your young and it prevents you from having kids and then take a second one later in life to be able to have kids or a spell that does it, also if magic is common in the lands this will bring out other changes which could increase harvests and increase the standard of living, but you would get other effects by magic being common most likely the lords and kings would be strong mages unless you deal with that in some way that dont require every mage to be alturistic. The point im trying to make is if you have a fantasy world that would mean that you could have other influances that removes this problem without the world becoming modern where magic have replaced tech it all depends how deep it goes and what influances the world you build have you could have the it be that you could plant stuff all year round with no winter.

    If all the starvations was because you had to many people and climat problems those are easy to get past without moving out of the middle ages just by having gods that they could pray where each prayer had an effect for example a god of birth that you could pray to for birth controll, god of weather for the weather and so on if the gods that exists affected change if prayed to it changes the equation to much to be able to really use a medival sociaty for a template for your sociaty so you would have to figure out those things what would change if you introduced magic what would stay the same and what could you introduce with magic that would change how the sociaty works.

    I have no doubt starvation was a big problem back in the day since the food production was lower and the birthrates higher this would lead to starvation and a lot of the wars were fought over just land to farm to increase the countries food production, also probobly the people living on that piece of land would probobly not survive since it would be better to bring in your own peasant to farm the land. Desease also played a big roll in bringing down how many mouths there was to fed.

  8. Magic does not seem to be common in the Fimbulwinter world. Remember that all the Margold soldiers were skeptical that he would be able to heal them at all. Then the Baron did not have a magic user of any sort, so his entire barony was without any magical help. Books of magic in the temple were chained down in a private room. When all is said and done I think we will find there are very few genuine magic users and that they hoard their knowledge.

    The other side of the coin is that the gods are definitely active in this world. Religious magic will probably play a larger role than that of wizards and sorcerors. It does seem though that religious magic comes at a much steeper price (shackles on Odin's altar).

  9. This makes a lot of sense, but I'd never thought of it. I'm more into science than history so things like this pass me by I guess. But it makes so very much sense.

    Somewhat horrifying I guess...

    As you're writing a guy from a modern era who's now in a place which would be affected by this law, does it get directly addressed in the story (perhaps Dark Coven or perhaps later?)