One reason why the soviet union grew slowly in the 20th century compared to the united states and western europe was that it:

The Communist Party of the Soviet Union followed Marxism-Leninism.  The party pursued state socialism which involved a nationalized and planned economy.  Without individual motivation, as was encouraged in the U.S., the people grew tired of working for the State.  The Soviet Union might have survived if  restructuring had taken place years before Gorbachev tried it and  their economy had become a market economy.  Instead it was allowed to grow stale and to stagnant which caused the collapse of the Soviet Union.   

Assemblies do not have written codes of laws. laws are matters for magistrates and courts, not assemblies. codes of law are things such as civil law, criminal law, and constitutional law. what assemblies have are procedures regarding debating, voting and other business they might carry out.  also note that rome had three assemblies: the assembly of the soldiers, the assembly of the tribes, and the plebeian councils.