The article discusses how certain social choice rules can be put into action using rational strategies. The researchers introduce a new concept called set-monotonicity, which is crucial for this implementation. They find that set-monotonicity is necessary and almost enough for rational implementation. This condition is less strict than Maskin monotonicity, which is needed for Nash implementation. In simpler terms, the conditions for rational implementation are different and less strict compared to Nash implementation when dealing with social choice rules.