The efficient markets hypothesis tells us that it's not possible to regularly beat the market. For information about what prices should be is already incorporated into those prices. Sure, some beat it for some period of time because that's just the way statistical variability works. Some, like Warren Buffett, beat it for a long time but then his cost of funds is lower than the market's.
We also have all sorts of people out there who insist that the use or markets to allocate economic resources is the wrong way to be doing it. That the wise people in government should be doing this for us instead perhaps.
At which point, an interesting comparison:
The message is clear: the beat-the-market efforts of professionals are impressively and overwhelmingly negative. In any asset class, the only consistently superior performer is the market itself. It is well to consider, briefly, the connection between the socialists and the active managers. I believe they are cut from the same cloth. What links them is a disbelief or skepticism about the efficacy of market prices in gathering and conveying information.
Odd to equate socialists and money managers, true. But the underlying point does stand. If we had evidence from our unfettered (no, don't titter at the back there) financial markets that they could consistently be beaten by good planners, then it's possible that good planners with adequate powers could improve upon a market economy.
We don't see that market outperformance - thus the planning part isn't going to work either, is it? For all the evidence we have is insisting that we cannot beat the market.