In addition, although OKUMA was considering bimetallism should be introduced as "nickel silver (Mexican dollar)"-based transaction was normal in Yokohama City as well as many other Asian countries, he decided the gold standard system would be introduced based on the proposal, "now, most countries are going to the gold standard system." by Hirobumi ITO, Okura no shofu (Junior Assistant Minister of the Ministry of the Treasury) and Minbu shohu (Junior Assistant Minister of Popular Affairs), who was on a business trip to the United States at that time.
また横浜市では、他の多くのアジア諸国と同様に「洋銀（メキシコドル）」での取引が常態化していたため、大隈としては金銀複本位制を考えていたが、当時アメリカ合衆国に出張中の大蔵少輔兼民部少輔伊藤博文の「現在、世界の大勢は金本位に向かいつつあり」との建言に基づき、金本位制の採用を決定する。