Origins of Agriculture
and Private Property
Bob Allen
Nuffield College
2008
The emergence of agriculture is
usually seen as progressive—
a great step forward
•
•
•
•
V Gordon Child called it the neolithic revolution
Permitted permanent settlements
Increased the food supply
Ushered in civilisation
–
–
–
–
–
Writing and numbers
Monumental architecture
Private property
The state
A non-working elite
With this view, it is obvious that agriculture was
adopted as soon as it was thought of. The problem is
explaining the great idea.
But that’s not how it was: the standard of
living fell when farming was adopted.
• In many cultures, people became shorter.
• Dental cavities and anaemia increased; other
indicators deteriorated.
• Farmers worked more hours per year than
foragers.
– Study of modern foragers.
According to Larsen, “Biological Changes in Human
Populations with Agriculture” (1995, p. 204),
“The shift from foraging to farming led to a reduction in health status
and well-being, an increase in physiological stress, a decline in nutrition,
an increase in birthrate and population growth, and an alteration of activity
types and [increased] work loads. Taken as a whole, then, the popular and
scholarly perception that quality of life improved with the acquisition of
agriculture is incorrect.”
Steckel-Rose (2002)
index of health declined
from foraging at left
thru agrarian
civilizations.
How can this paradox be explained?
• Why did people take up farming if their
standard of living declined?
• Why didn’t agriculture improve human well
being?
• A test for any theory of the origins of
agriculture is to reconcile farming with falling
living standards.
To answer these questions, we must
develop a model
• that distinguishes exogenous from endogenous
variables
• includes production and demography
• incorporates feed back between the two
• is based on the important ‘stylized facts’ of
archaeology.
Before developing this model, we will review the
history of the ‘invention’ of agriculture.
Agriculture appeared in seven regions
between 4K and 10K years ago:
I concentrate on the Near East where wheat, barley, lentils, flax,
sheep, goats, pigs, cattle were domesticated.
Habitats of wild progenitors of wheat & barley and area
(in brown) where domestication occurred.
Original habitat of wild sheep and area of domestication
(% sheep bones in bone assemblages, 9000-8200 BP).
The Natufians (14500-11500 BP)
were the people who domesticated cereals.
• They typically lived where hills met plains.
• Gazelle lived on the plains and were hunted.
• The hills contained oaks and pistachios which
gave nuts as food.
• Also on the hillsides were stands of wild wheat
and barley, which they harvested.
• They lived in semi-subterranean houses with
stone foundations and probably wood
superstructures.
Natufian landscape
Wild barley growing on a hillside
Natufian tools included:
•
•
•
•
Flat bladed sickles
Mortars
Grinding stones
Storage pits
• Abundance of tools for harvesting and
preparing grain shows its importance in their
diet.
Sickle and grinding stones
Modern foragers know a lot about the
plants and animals they harvest.
• How they reproduce.
• How the environment affects their growth
(they even garden them).
• The realization that planting seeds yielded
crops was not an intellectual breakthrough that
precipitated farming since it was probably
known for a long time.
Domestication was inadvertent
• Farmers began by planting wild seed and
keeping wild animals.
• Domestication implies biological changes that
made wild varieties easier for human beings to
manage.
• Evidence of domesticated barley as early as
11000 BP.
• Wheat domesticated by 9800 BP.
• Sheep and goats about the same time.
With animals, domestication meant
that the animal got smaller.
• Animals were tethered, and not fed very much.
• They were smaller as a result.
• Females, in particular, were smaller and had
smaller birth canals.
• They could no longer give birth to large
offspring.
• Inadvertent selection for genetically smaller
animals.
Wild sheep had bigger bones:
Morphology of plants also changed
• In the wild, seed cases were flimsy.
• As a result, wild seed dispersed easily.
• When humans harvested wild seed, it
dispersed, and much of it was lost as it was
harvested and taken to houses.
• Domestication meant harder seed cases, which
reduced losses.
• Threshing was necessary to break seed cases.
Brittle rachis and tough rachis
How did this change happen? And
without anybody knowing about it?
• About one wild plant in 2 – 4 million had a tough racchis.
• Humans could have inadvertently produced predominantly
hard racchis seed (ie domesticate wheat) in 200 years, if they
– Didn’t begin the harvest of wild seed until the grain was ripe and the
soft racchis seed was falling to the ground.
– Harvested wild wheat with a sickle and left grain that fell off on the
ground.
– Planted seed where it could not interbreed with wild seed.
• Evidently, cultivation preceded domestication.
• Domestication required a shift in the location of cultivation.
Changes in temperature since end of
ice age 15000 BP played a key role.
(Younger Dryas)
End of Ice Age
The story goes like this:
• Rise in temperature and rainfall 15K BP increased
fertility of the environment and made it possible for
the Natufians to harvest wild cereals.
• The ‘younger dryas’ was colder and drier and made
existing settlements unsustainable.
• People moved and began cultivating wheat and barley
near rivers.
• This triggered domestication.
• When climate improved, agriculture was more
productive than foraging and displaced it.
There may be some truth to this theory,
but it is not the whole story.
• The theory predicts a temporary fall in income
as the climate deteriorated.
• Then the standard of living is predicted to
rebound.
• That is not what happened.
• To model this, we must include demographic
model.
We use a Malthusian positive check
demographic model:
Birth &
Death
rates
BR=birth rate
DR=death rate
w = equilibrium income
Income per person = food consumption/ head
We need a production model with
diminishing returns to labour:
Food/
head
w
L
labour
The yellow productivity line could be either:
• average product of labour
– If the land is an open access common
– If ‘residents’ have rights to use specific tracts of land so
long as they live in the village and if those rights cannot be
let or sold (like Russian mir).
• marginal product of labour
– If people have rights to specific tracts of land that they can
use, sell, or lease as they like.
For the moment, I assume that yellow line is the
average product of labour.
We can place the demographic and productivity
graphs side by side and show the equilibrium:
BR
DR
Food/
head
w*
L*
0
< = birth & death rates
labour = >
Any other wage and population levels generate population
changes that move population towards w* and L*
BR
DR
Food/
head
w*
w
D>B (so L=>L*) 0
< = birth & death rates
L*
labour = >
L
We need to allocate labour between
two activities, farming and foraging:
food/
head
food/
head
w
w
0
foraging labour = >
< = farming labour
0
In this version of the diagram, there are
only foragers, because foraging is
always more productive:
food/
head
food/
head
w
w
0
foraging labour = >
< = farming labour
0
Natufian foraging equilibrium
Food/head
BR
DR
foraging productivity on hill sides
farming
productivity
by rivers
foraging population
Dry conditions led to farming and a fall in income
Food/head
BR
DR
lower
foraging productivity on hill sides
short run
equilibrium
with lower
income &
declining
population
farming
productivity
with wild seed
by rivers
foraging
population
farming
population
Note: The long run equilibrium is one in which there is no population!
inadvertent seed selection makes farming competitive
but income remains at foraging level
Food/head
BR
DR
foraging productivity
forager = farming income
farming
productivity
with
domesticates
foraging
population
productivity
with wild
seed
farming
population
There are other themes that point to a
more satisfactory theory:
• Cohen (1977) advanced ‘population pressure’
as an explanation.
– An objection is: why did the population grow
without a food supply?
• Hayden (1990)—competitive feasting
• Weisdorf (2003)—manufactures
– This may work in China where pottery was
invented before grain was domesticated.
Another important point of departure is that
permanent settlements preceded farming
• Inversion of the Child paradigm where
agriculture leads to permanent settlements.
• Established for the Natufians by Ofer bar
Yosef who studied the noses of mice.
• Explanation: rising temperature after last ice
age increased fertility of the natural
environment, reducing the distance people
needed to wander to find food. Eventually,
they could stay in one place and make day
trips.
Permanent settlement affected many
aspects of human life:
• Since people did not have to carry their babies,
they could have more of them, and the fertility
rate rose.
– Ethnographic evidence
– Expectation of life decreased
• In some places, manufactures (eg pottery)
were invented before farming
• Communal activities like feasting
The rise in fertility was probably the
operative factor among the Natufians.
• On its own, it was sufficient to lead to agriculture.
• ‘Population pressure’ is involved, but why it occurred
is clarified.
• People avoided planting wild seed by rivers since that
involved more work (removing other plants that were
dominant).
• They only planted seed by rivers when they became
poor enough.
• This analysis explains why the invention of
agriculture was accompanied by a permanent fall in
the standard of living.
Natufian foraging equilibrium
Food/head
BR
DR
foraging productivity
foraging income
farming
productivity
foraging population
sedentism leads to farming
Food/head
BR
Higher
Birth
Rate
DR
foraging productivity
forager income
farming income
farming productivity
with wild seed
foraging population
Farming population
inadvertent seed selection makes farming competitive
Food/head
BR
Higher
Birth
Rate
DR
foraging productivity
higher
farming
productivity
with domesticates
productivity
with wild
seed
foraging population
Farming population
Notice that the sedentism theory:
• Means that the adoption of agriculture is
associated with population growth
• The adoption of agriculture was accompanied
by a permanent decline in the standard of
living.
• This theory can apply anywhere and may
explain why agriculture was ‘discovered’ in so
many places.
The Younger Dryas theory can explain domestication, but it does
not imply a permanent decline in the standard of living.
• In the long run, income depends on birth and
death rate functions. and they do not change
under this scenario.
• Dry conditions may have ‘nudged’ the
Natufians towards planting seeds by rivers, but
that would have happened anyway.
The analysis assumes communal ownership of
property with temporary individual use rights.
• This was Marx’s primitive communism.
• Are there any forces that would generate
private property?
• If there is enough heterogeneity in the land and
people, then private property has efficiency
advantages.
Private property means that land can be
leased or sold.
• There can be non-working land lords (exploitation).
• Labour is allocated across the land to equate the
marginal product of labour rather than its average
product.
– With some simple functions, the allocation is the same.
• If the allocation is different, then total output
increases.
• In that case, there are efficiency gains from private
property, so winners can compensate losers.
If land is homogeneous, so every plot has the same
production function, then there is no advantage to
private property.
average products
Marginal products
OA
OB
Average product and marginal product curves intersect at the same labour value.
If land is heterogeneous, then there is an
advantage to private property.
This triangle is the dead weight loss from communal property
average products
Marginal products
OA
A
M
OB
If land is homogeneous, so every plot has the same
production function, then there is no advantage to private
property.
• Q/LA = 1 – ¼ LA and Q/LB = 1 – ¼ LB and
LA+LB=2
• Average product equalization => LA= LB=1
• Total product is Q = LA – ¼ LA2
• Marginal product is dQ/dLA = 1 – ½ LA
• Equating marginal prod’s 1 – ½ LA = 1 – ½ LB
• Implies that LA= LB=1
If land is heterogeneous, then there is an advantage to
private property.
• Q/LA = 1 – ¼ LA and Q/LB = 5/4 – ¼ LB and
LA+LB=2
• Average product equalization LA= ½, LB=3/2
• Total product is Q = LA – ¼ LA2
• Q = 5/4 LB – ¼ LB2
• total product is 1.75.
Marginal product equalization gives
more output
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•
•
•
•
•
Marginal product is dQ/dLA = 1 – ½ LA
Marginal product is dQ/dLB = 5/4 – ½ LB
Equating marginal products:
1 – ½ LA = 5/4 – ½ LB
Implies that LA= ¾ and LB= 5/4
Total product is 1.78125
With heterogeneous land, the
invention of private property was
socially progressive.
Of course, the standard of
living would not rise—
only the population!