366 LAND REFORM
converted to bushels per acre, the amount would be 15.29 bushels/acre for 1400,
22.33 bushels/acre for 1770, and 26.73 bushels/acre for IS50.3S Perkins calcu-
lated yields in the twentieth century at 242 catties/shih mou for 1933, and 274
catties/shih mou for 1957, or 26.62 and 30.14 bushels/acre. The bushels/acre
figure of 27 bushels for I S50 is close to double Korea's output, and 30 for 1933
is still ahead of Korea's at that time.3^6
By the mid-1(.)20S Korean productivity had risen beyond the 15.5 bushels/acre
of 1910. Hoon K. Lee found an average rice yield in the 1921-25 period of IS.SI
bushels per acre, a time when about half the rice crop was planted in improved
varieties of seed introduced after 1910, while Hishimoto Ch6ji reported rice pro-
ductivity in I9IS at 20 bushels/acre.:^17
In summary, the average productivity of the rice crop in Korea in 1910 was
significantly less than Japan or China, but this measure does not take into account
total food production.The Grmt'th of Population and Per-capita ProductivityEstimating the national population for the pre-twentieth century period is
fraught with difficulty because of the unreliability of traditional government sta-
tistics in the Choson period. Demographers agree that the figures for the num-
ber of persons in the traditional records cannot be accepted, and Tony Michell's
demographic study has been based on statistics for households multiplied by a
crude estimate that includes a guess about a uniform level ofunderreporting.ln
any case, he has written that the Korean population grew steadily from about
4-4 million people at the beginning of the dynasty to about 9.S million just prior
to Hideyoshi's invasions in 1592, an average growth of 0.61 percent a year for
the 200-year period. It then dropped by as much as 20 percent or 2 million dur-
ing the Imjin War, and did not reattain the 1592 level until about 1650. The pop-
ulation continued to increase to 12.3 million by 1693. when a famine from 1693
to 1695 caused another severe drop to 10.2 million. Recovery occurred by about
1717 and further growth continued to 13.6 million by 1732. Several population
crises occurred thereafter in the eighteenth century, which interrupted short -term
trends toward population increase. The population achieved 14 million by I S 10
before the crisis of I S I 2-13, when it dropped to 12-4 million by 18 I 6, There-
after the population fluctuated between 12.2 and 12.7 million to 1876, a million
less than the eighteenth century.,8
Kim Yongsop, Yi Chunyong, and Michell have argued that the production of
rice and barley, even millet and beans, increased after the Tmjin War of 1592-98
because of the expansion of wet rice cultivation and transplantation on paddy
land, the suddcn expansion of irrigation through the construction of reservoirs
and pouldcrs, double cropping, particularly of rice and barley on paddy fields,
and the introduction of new crops like red peppers, gourds. and tobacco. Trans-
planting sprcad evcrywherc except the northern provinces by 1674, and the