Variables

Implication

Expected Symbol

Theoretical Assumptions

GDPit

GDP of Japan’s source of import

It reflects soybean export supply ability of source of imports, the greater the amount of economic scale, the greater the potential ability to export, the greater the Japan’s soybean import

GDPjt

Japan’s GDP

It reflects the Japan’s soybean import demand, the greater the amount of economic scale, the greater the potential ability to import, the greater the soybean import

POPit

Population of Japan’s source of import

The more a country’s population, the larger the domestic market scale, the less need to rely on the international market, and smaller export scale, the smaller Japan’s soybean import

POPjt

Population of Japan

It reflects the Japan’s soybean import demand, the more population, the greater the demand, the greater the import

Dijt

The linear distance from Tokyo to capital or economic center of source of import

The farther the distance, the greater the cost of transportation, the smaller the import

Pijt

The soybean import price from Japan’s source of import

It reflects the supply ability of soybean source of imports, import price rises, Japan will reduce soybean import from the country

RATEijt

The exchange rate of source of imports currency against yen

It reflects the influence on Japan’s soybean import by bilateral exchange rate, the decrease of exchange rate means that Japan will pay a higher price, it will cause soybean import reduced

PORit

Annual soybean production of source of import

It reflects the soybean supply ability of the source of imports, the higher the annual output, the stronger the soybean supply ability, the greater Japan’s import

CONjt

Japan’s annual soybean consumption

It reflects the Japan’s soybean demand, the greater the annual consumption, the greater the demand for soybean import

STOit

Soybean stocks of source of import

It reflects the soybean supply ability of source of imports, while domestic consumption remains the same, the more stocks shows the less potential exports, the less Japan’s import

STOjt

Japan’s soybean stocks

It reflects the Japan’s soybean demand, when consumption remains the same, the more the stocks, the less soybean import need

LANDjt

Japan’s soybean harvested area

It reflects the Japan’s soybean supply ability, the bigger the harvested area, the stronger the self-sufficiency, the less the import

OILjt

Japan’s soybean oil import volume

It reflects the substitution effect of soybean oil import on soybean import, the more soybean oil import, the less soybean import

T

Virtual variable of Japan’s implementation of the policy to labeling of GM food

After implementation to labeling of GM food, because the consumer awareness of GM, soybean import decreases

F

Virtual variable of the 2008 financial crisis

After the outbreak of the financial crisis, the global economic recession began, Japan’s demand and source of imports supply capacity both decreased, soybean import decreased