I've been listening to Gregory Clark's
World
Economic History -- Pre-Hsitory to the Industrial Revolution class
on iTunes U. The class, taught out of Clark's popular
A
Farewell To Alms, is devoted to Clark's thesis that prior to the
Industrial Revolution all humans mostly lived on the Malthusian
frontier [
*]. That is to
say that the population level is maintained in equilibrium between
population and resource levels/income. Anything that adjusts these
factors temporarily removes the system from equilibrium, but
homeostasis quickly reasserts itself. So, for instance, if there is
some new technology that increases crop yields, people respond by
having more children or by living longer (whether consciously or
because being better fed makes you more fertile and live longer) and
thus population increases with little or no likely impact on overall
standard of living. Thus (Clark argues) there was nearly no net
improvement in standard of living from the Neolithic to the Industrial
Revolution.
As I understand it, Clark argues that two factors acted to change this
state of affairs. First, technological change accelerated to the
point where the the amount of resources that could be exploited was
changing faster than the time scale on which birth and death rates
responded, keeping the system permanently out of equilibrium.
Second, people started practicing real fertility control, which
acts to damp the population response to higher income levels
(and of course there are natural limits on how much lifespan
can increase solely on the basis of income.) [There's also a whole
bunch of stuff about how these changes are due to cultural and
biological evolution as a result of differential reproduction between
the rich and the poor, but I don't want to talk about that just yet.]
Much of the first half of the course is devoted to explicating the
model, and in classic counterintuitive economist style, Clark makes
a big point about how in the Malthusian world, things that you
ordinarily think of as good are bad, and vice versa. To take on
example, if a horrible disease gets introduced into your society
so that it increases the death rate by 10%, that leaves
more resources for everyone else with the result that the people
who don't die of plague have a higher overall standard of living.
Here's Clark's Table 2.2 (page 37 of "A Farewall to Alms"):
| Malthusian "Virtues" and "Vices" |
| "Virtues" | "Vices" |
| Fertility limitation | Fecundity |
| Bad sanitation | Cleanliness |
| Violence | Peace |
| Harvest failures | Public granaries |
| Infanticide | Parental solicitude |
| Income inequality | Income equality |
| Selfishness | Charity |
| Indolence | Hard work |
Note the scare quotes around virtues and vices. Clark sort
of equivocates between the view that societies with
short life spans and high material standards of living
are really better and the view that income levels are
just one instrument. For instance, on page 36 he writes:
In summary table 2.2 shows Malthusian "virtues"
and "vices." But virtue and vice here are measured with reference
only to whether actions raised or lowered material income per person.
This sort of supports the "it's just an instrument" view but
then on page 38 Clark writes:
The failure of settled agriculture to improve living conditions,
and the possibility that living conditions fell with the arrival of
agricultire, have led some economists, anthropologists, and archaeologists
to puzzle over why mankind abandoned the superior hunter-gatherer
lifestyle for inferior agrarian societies.
This argument isn't a new one. In fact, this specific form of the
argument was famously made by Diamond's The Worst Mistake in the History of the Human Race.
Clark comes back to the more general theme repeatedly, and suggests
in a number of places during the class that people in fact would prefer to live in
societies with a lot of disease and violence but correspondingly
higher material living standards (though again, there is some ambiguity
about the level to which he is actually endorsing this view.)
It seems to me that one ought to raise at least two objections to this
general line of argument. First, it's not at all obvious that it's
that useful to assess people's welfare by their income level (or as I
once heard it put more crudely, by the number of calories they are
able to consume per day.) [I wish I could remember where I read this.]
First, to a great degree human sense of how happy they are is
positional, so if everyone in society gets 100% richer, that doesn't
make everyone 100% happier, it's just that instead of being jealous of
the guy next to me at the stop light in his Audi RS4, I'm now jealous
that he has a 911 Turbo; not much of a net win. Second,
in the Malthusian model a lot of the "virtues" that result in
a higher standard of living are things people find really
unpleasant. In particular, random violence, crop failures, and
disease (and uncertainty in general) is incredibly stressful
(see Sapolsky's Why Zebras Don't Get Ulcers for a good primer
on this.) It's not clear at all that people in general
would rather trade much higher rates of catastrophic events
for a somewhat higher level of expected welfare if you survive.
Clark does offer some arguments that people make choices along these
lines, for instance that people voluntarily joined the East India
Company even though the risks were very high, but it's not clear
that it's really that useful to use the risk/reward behaviors
of 20-year old male adventure seekers as a stand-in for the entire
society.
Even if we are to concede that people are individually happier in
societies with high violence and disease rates (and hence lower
populations) but high standards of living than they would be in
societies with lower violence and disease rates (and hence higher
populations) but correspondingly lower standards of living, that does
not mean that those societies are truly more desirable. (See, for
instance Parfit's "Only France Survives"
in Reasons and Persons). Surely, most people in societies
with a low standard of living would nevertheless prefer to be alive
than dead, even if dead would mean that other people would live
better, so it's difficult to say that the society with the
lower population is better, especially when that equilibrium is
obtained by high death rates (i.e., the killing of people who exist
and have their own interests) rather than low birth rates
(i.e., the nonexistence of people who might otherwise exist.)