China’s Money Supply Has Outgrown Its Economy over Two Fold Since 2009 (thesoundingline.com)

The ability to semi-tinker with the economy may lead to leaders with a false sense of full control. They may find a way to shuffle things around to hide problems most of the time, but eventually they'll make a mistake, all humans do, and create a problem bigger than further meddling can fix or delay. Historically, autocrats try to fix big economic problems in ham-handed ways that make the problem worse.

This is not to say that open systems don't also have problems, but it's harder to sweep things under the rug when your political competitors can and do broadcast all your mistakes to the public. Checks and balances.