how did hayes suggestion of an open door policy in china benefit the united states over other nations

The United States produced goods of better quality and lower cost than other countries.

Explanation:

The Open Door Agreement was a trade arrangement with many European nations , including France, Italy , Japan, Russia and other nations having a stronghold in China.  The U.S Secretary of State John Hay established this policy to enable the US, Japan, and other European countries to have fair trade access to China. It was formulated at the beginning of the twentieth century to secure the trade interest and imperialist policies of the United States in China.