There are no good evaluations that clearly show it. It seems to me to be a reasonable expectation that at least while it's on your ankle, you're maybe trying to be on your best behaviour, but in looking at the evaluations, it's not clear. It's not as if we can confidently say that crime is reduced while the bracelet is on. However, what's very clear is that once you take the bracelet off, there's no long-term impact.
On February 9th, 2012. See this statement in context.