A couple of years ago, former Obama and Bush officials estimated that only 1 percent of government spending is backed by any evidence at all. 1 percent. Perhaps unsurprisingly, then, evaluations of government-sponsored school and work programs have found that some three-quarters of those have no effect.
Evidence requires running good studies. Running controlled studies requires treating some people differently then other people based on arbitrary criteria. Treating everybody the same in front of the law is a basic principle in many countries which discourages the running of controlled studies.
Is not as simple as you think. Evidence is hard. If the evidence were easy and simple it would already be in use.
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Evidence requires running good studies. Running controlled studies requires treating some people differently then other people based on arbitrary criteria. Treating everybody the same in front of the law is a basic principle in many countries which discourages the running of controlled studies.