Downward harmonization

Downward harmonization is when a group of things that are supposed to be the same become less good over time because they all become more like the least good thing in the group.

For example, think about a group of friends who all have different toys. Some of them have really cool and expensive toys, while others have cheaper and less exciting toys. If all of the friends start sharing their toys, it might be fun at first. However, over time, the ones with the cool toys might get tired of sharing with the ones who only have boring toys. So, they might start playing with their toys less or bringing cheaper toys to share instead.

This is an example of downward harmonization because the quality of the group's toys has decreased over time. The better toys have become more like the worse ones in the group. This can happen in many different situations like when countries are trying to make laws or when companies are trying to set standards.