It seems quite obvious that 'competition' between the various 'planned economies' and choice between them by consumers is generally a good thing. One that would

It seems quite obvious that 'competition' between the various 'planned economies' and choice between them by consumers is generally a good thing. One that would not work for a fully centrally planned economy. That said, it is indeed quite interesting to figure out at what size such central planning starts to become non viable. And for that the observations: "It is viable for wallmart, but not for all of the USA" give some interesting bounds.