110 THE ROMAN EMPIRE
1 Rome’s subsistence requirement (food only) in wheat equivalent:
200,000 tonnes p.a.
2 Rome’s subsistence requirement in wheat alone: 150,000 tonnes p.a.,
around 22.5 million modii, assuming wheat made up 75 per cent of
total food energy requirements.
3 The requirement for the grain dole ( frumentatio ) in wheat: 80,000
tonnes, or 12 million modii, for 200,000 recipients, at 5 modii per
person/month. (Or, 100,000 tonnes, 15 million modii, for 250,000
recipients.)
4 Actual consumption rate of wheat: around 200,000 tonnes, or
30 million modii, p.a.
5 Total wheat imports: variable, in the range of 200,000–400,000
tonnes, or 30–60 million modii, p.a.
The fi rst fi gure is the total subsistence requirement, food only (housing,
clothing, etc., excluded), measured in terms of the prime staple, wheat. The
assumption is that around 1700 calories are needed per person/day. At the
ratio of approximately 3000 calories to 1 kg wheat, 200 kg minimum are
required per person/year, thus 200 million kg or 200,000 tonnes for one
million people. For completeness, it would be necessary to furnish estimates
of how much food was consumed and imported, both in terms of wheat
equivalent.
The remaining estimates are in terms of wheat, the main staple. The
peculiar signifi cance of wheat in dietary and political terms is implied in the
special treatment it received in imperial Rome, as in classical Athens. Grain
alone was distributed in Rome until the turn of the second century AD.
The second estimate is the wheat required by Rome’s inhabitants for
subsistence: this amounts to three quarters of the previous fi gure, or 150,000
tonnes. One might make a case for a lower percentage fi gure for wheat, to
refl ect the relatively favourable position of Roman consumers. Modern
evidence shows that the percentage of cereals in the diet decreases as
prosperity increases. But did the majority of Roman consumers become
more prosperous, and how far were alternative sources of food energy
available, meat in particular, at prices they could afford? Prices were high in
Rome. Salaries were also high, but then unemployment and underemployment
were rife, as in third- world cities today.
The third fi gure, 80,000 tonnes or 12 million modii, the amount of wheat
needed for the hand- out, needs no further explanation.
The fourth fi gure, 200,000 tonnes or 30 million modii, represents annual
wheat consumption. Some favour a much higher fi gure, as much as 400,000
tonnes, or double our estimate.^2 That fi gure is a product of the juxtaposition
of two isolated literary texts, both unreliable, one dating to the mid- fourth
century, the other to the mid- fi rst. The former ( Caes. 1.6) gives a fi gure of
20 million modii for Egyptian wheat exported to Rome under Augustus