According to the European Commission (1996g), in 1980 one-way trade accounted for justbelow 47.5% of all trade among the 12 EU countries, vertical intra-industry trade accounted for approximately35.0%, and horizontal intra-industry trade was approximately 17.5%. By 1994, however, vertical intra-industrytrade was the most common type with approximately 42.3%, followed by one-way trade with approximately38.5% and horizontal intra-industry trade with approximately 19.2%. European Commission(1996g)によれば、EU12か国の域内貿易は、1980年には一方向貿易の割合が全体の47.5%弱を占め、垂直的産業内貿易が約35.0%、水平的産業内貿易が約17.5%という構成であったが、1994年には、垂直的産業内貿易が約42.3%と最も多くなり、次いで一方向貿易が約38.5%、水平的産業内貿易が約19.2%へと変化した。 - 経済産業省