Yu 's A N A L Y SIS 0 F CUR R ENe Y 897
divert attention away from the production of food and clothing. In this instance,
I would suspect that Yu Hyongwon had decided to cite Yeh's work because he
admired the thrust of his argument, not because he regarded it as absurd.
Fluctuations in Sung Dynasty Money Supply. According to Yu's account, after
the fall of the T'ang dynasty, cash went out of use briefly until Emperor Shih-
tsung (r. 944-60) of the Later Chou dynasty confiscated copper utensils and Bud-
dhist statuary and resumed minting different types of coins after 960. For the
Sung dynasty, founded that very year, however, the cash glut became the source
of problems as Yeh had pointed out. Yu cited Ch'iu Chlin's criticism of the Sung
emperors' habit of minting new coins every time they changed the year period
within a reign. Emperor len-tsung changed year periods nine times in the forty
years of his reign with a coin for each, and the costs involved in minting new
cash, such as finding copper are, smelting the are or melting down scrap cop-
per, employing artisans and workers, and paying for supervisors and officials
placed an enormous burden on the population.'o
From the time of Wang An-shih's administration at court after I068, the sup-
ply of copper available for cash and state finances had been depleted. Yu attrib-
uted the phenomenon to the abandonment of the prohibition against private
ownership of copper and the failure of the government to prevent the export of
copper or cash from the country by ship.
By subscribing to the first of these two explanations, Yu indicated that he might
have been won over to the views of Emperor Hsien-tsung and Yeh Ming-te except
that he also saw fit to quote the argument of Hu Hung (?) (I IOO-55), who
explained that the main reason for the cash shortage was that people were melt-
ing copper cash and selling raw copper because it was then worth ten times more
than the face value of the copper cash. Hu argued that the emperor could coun-
teract this trend by imposing a prohibition against melting cash down, a more
economical way of maintaining the supply of cash than by minting more of it.
Failure to maintain the ban against the export of copper utensils only exacer-
bated the problem because it meant that copper would end up in the hands of
the "barbarians," bona fide cash would shrink in quantity, counterfeit cash would
rise, and the possibility of finding enough copper to meet the need for cash would
be lostY
What was important about Hu's critique was that it demonstrated that the sup-
ply of copper was the crucial factor in explaning a cash shortage, and that the
price of copper ore relative to the value of cash and foreign trade in copper
were instrumental in explaining both why a shortage might exist, or how it could
be solved.
Paper Money: In Sung, Chin, and Yuan Dynasties. Yu ended his discussion
of currency with a special section on paper money, first introduced in Sung China.
During the reign of Emperor Chen-tsung (r. 997-I022), Chang Yung, the local
military commander in the Szechwan area who was dissatisfied with iron cash
because it was too heavy, began to circulate paper scrip (chih-chi) called chiao-
tzu in which each piece of paper money was designated as equivalent to one