My read on this was that it's a useful metaphor for the economy, with the state as the rider and the horse as the industrial base. The original communist idea w

My read on this was that it's a useful metaphor for the economy, with the state as the rider and the horse as the industrial base. The original communist idea was to direct industrial output in some detail, which worked about as well as trying to control the individual muscles of a horse. The US, meanwhile, directs the economy by deciding "I want $X billion dollars worth of helicopters" and then letting the private sector figure out the low-level actions required to get there. The Chinese are probably an even better example in this regard.