Summary: Present a bad idea first like "let's go to McDonald's for lunch" and let people involve in decision making because they won't like it.
Decision making is an important process to take things forward and good decisions are crucial for better results.
Contribution is very important to make good decisions, even the best decision can be improved with contribution from other people.
And we know it is not easy to make people contribute into making decisions. At this point McDonald's Theory is here to help!
So you are in a meeting and you propose a possible decision. Everybody thinks it is okay however you know it is not enough. You want people to contribute but since the decision is okay, people don't contribute much.
People fear that they will shut down if they present an idea that is not good enough.
What if you suggest a bad and unacceptable idea first? Like if you are trying to find where to go for lunch, start with "Let's go to McDonald's for lunch, any other ideas?". Others will not like it and they try to come up with better ones. There you go, you have the contribution gear started.
McDonald's Theory is useful for businesses and you may read the rest of the article from here written by Jon Bell.