Here is what I wanted to send before Eudora 5.1 decided to crash and send off the last saved (incomplete) version of my comment. s.
Maoist China is hardly a poster boy of planned system. Where I lived there during the so-called cultural revolution I saw a lot of oppression, especially of the urban folks, and a lot of inefficiency (e.g. rural coops producing low-tech goods as a "solution" for decentralization and development). Not exactly the model for the 21st century. What I saw was basically an elite whose power base was in the country side and who feared the city (working class and intelligentsia) - in essence a phenomenon similar to Khmer Rouge and Taliban.
Populist arguments for the planned system (e.g. the masses will lead) are nothing but hot air - political propaganda designed to legitimate a power elite that came to power on the wave of peasant discontent in China. Its appeal in the US (and to a lesser extent Western Europe) is linked to the popularity of noble-savage archetype among some of the loonie-antiestablishment elements.
The main weakness of the populist argument for the planned system is its lack of specificity how exactly "the masses" will plan economy and society. The neo-classical rat-choice "free-rider argument sounds like the words of wisdom vis a vis such populist mumbo-jumbo. Such argument do the idea of a planned system more harm than good.
A much stronger argument for a planned economy has been advanced by transaction cost and institutional economists. Here is what I wrote about it:
Well, there is such a thing as transaction cost economics (TCE) of which the writer seems blissfully oblivious. The basic aTCE argument goes as follows: there is a cost to every business transaction carried under a free market condition (e.g. surveying the market, drafting and enforcing contracts, dealing with contingencies, etc.); the more complex the economy, the more transaction it requires, and thus the higher the transaction cost; transaction cost can be substantially reduced, inter alia, by "organizational hierarchies" (TCE lingo for planning; ergo - in complex economies large monopolistic organizational structures can be more efficient than free markets.
In essence, the argument for a planned system is that it is more efficient than free market because it eliminates a lots of transaction costs and negative externalities generated by the latter - I guess that argument is essentially in line with the Baran-Sweezy classic.
Another problem with the populist appeal to the masses is that as the surplus and thus standards of living increase, the masses cease to be masses and start seeing themselves as individuals with unique needs. Populistic mass society identity has very little appeal to them. That is why they opt for consumerist ideologies, readily supplied to them by "bourgeois" ideologues, while the left keeps playing its hackneyed "masses-schmasses" mantra.
wojtek