An experiment is a procedure carried out to support, refute, or validate a hypothesis. Experiments provide insight into cause-and-effect by demonstrating what outcome occurs when a particular factor is manipulated. Experiments vary greatly in goal and scale, but always rely on repeatable procedure and logical analysis of the results.
now it's my turn to pick on your words :P decentralization as a political system is an idea, a concept, a system. You don't experiment with ideas, you implement them :)
Sure and the hypothesis is that a political system will work. Anytime you try something knew you are working on a hypothesis that what you are about to attempt could be the solution to a problem. ;)
Physics is an idea. Newtonia physics is an idea. Relativity is an idea. Quantum physics is an idea. Engineering is an idea. All ideas do start as a hypothesis. You are correct that an experiment is performed to either prove, or disprove a hypothesis. Which is what should be done. It should be attempted and proven it will not work before simply saying it won't work. :)