Sorry, I don't think this experiment can prove anything. You have mentioned Japan have their unique police to handle this kind of things, in fact, in China, each public places have an individual office which duty to save lost goods or help people to find their lost. According to this, the most times, we do not need to call the police. In addition, email is not a common contact method for Chinese people, we often use wechat. I hope the writer can have more scientific research before you give any comment for a country or their people.