W.W. Farris
Shōsōin documents, particularly the household and tax registers (koseki; keichō), provide insights
into population unavailable for any other society during the 700s.^13
Sawada Goichi (1861–1931) was the first scholar to make a lasting contribution to Nara demo-
graphy by estimating a total population of 6–7 million for Japan during the reign of Emperor
Shōmu (724–749). This amazing feat he accomplished by two methods. First, referring to an
early tenth- century legal source (the Engi shiki, or “Ordinances of Engi”) that listed the total
number of rice sheaves loaned out as a tax for each of Japan’s sixty- six provinces, he utilized a
regulation (kyaku) from lonely Mutsu province in 815 enumerating the total number of taxable
males for that province to calculate the number of taxable males per 1,000 rice sheaves. That
number was 27.07. Then, availing himself of the most accurate household registers for the eighth
century, he derived the proportion of taxable males to the rest of the population, added the two
together, and found the total commoner population at 5.5 million. Combining that total with
the urban population of Nara and the tally for slaves and vagabonds, Sawada reasoned that the
total population for early Nara Japan was 6–7 million.
Sawada then utilized a second method to arrive at a similar figure. He began by citing a 747
order enumerating the desired number of taxable males in “sustenance households” (fuko), a type
of aristocratic revenue source. Availing himself of extant household registers, Sawada calculated
that the average administrative village (gō or ri) contained about 1,400 persons. He then multi-
plied that figure by the total number of villages listed in an early tenth- century source called the
Wamyō shō and once again came up with a commoner population of 5.5 million and total of 6–7
million.^14 As the dean of Japanese demographers, Hayami Akira, has stated, Sawada’s estimate
comprises the one figure for pre-1700 Japan upon which scholars can rely.
Even so, various historians have toyed with Sawada’s methods to suit their agendas. Kamata
Motokazu of Kyoto University authored the most serious of these challenges. Reasoning that
the number of taxable males included in “sustenance households” was artificially high to benefit
aristocratic recipients, he recomputed the size of the average administrative household at only
1,052. Then multiplying by the total administrative villages contained in the Wamyō shō, Kamata
arrived at a total population of 4,251,132 for Japan around 747, and posited that Japan’s popu-
lation had grown to six million or so by 800.^15
To be sure, some may have reservations about Sawada’s estimate. For example, with regard to
method one, how can anyone be certain that the number of taxable males in sparsely settled
Mutsu in northeastern Japan could be representative of the more densely populated regions of
Japan? Certainly his estimate for Nara (200,000) was too high; a figure of 70–100,000 seems
more reasonable.^16 Moreover, how can an early tenth- century total of villages found in the
Wamyō shō fit Japan during the mid- 700s—as it is assumed to in both Sawada’s method two and
Kamata’s calculation? Sawada’s estimate may have been widely accepted, but doubts could be
entertained about its exactitude.
As often happens in Japanese scholarship, an archaeological discovery lent unexpected support
to Sawada’s work. Excavation at a site located in the northern Kanto uncovered lacquer- soaked
records, one of which listed the population for Hitachi province at 192,000.^17 As interpreted by
Kamata, the total population for archaic Hitachi province would have been about 224–244,000,
just a tiny fraction more than Sawada’s 217,000. Now scholars had independent corroboration
for Sawada’s estimate and his methods. Writing in 2009, I also gave implicit support to Sawada’s
work, estimating Japan’s population between 715 and 739 at 5.8–6.4 million.^18
I made another lasting contribution to the study of Nara population in 1985.^19 Japanese histo-
rians had long known of a smallpox epidemic that had struck the archipelago during 735–737.
The world historian William McNeill had had access to a translation of Japanese disease materials
originating from the late seventh to the thirteenth century and had proposed that ancient Japan