the model which china imported for its economic progress was basically an american/western capitalistic model liberalization of chinese economy started all the economic growth and where china is today, china also had a good fortune to be near japanese and korean economies which invested a lot in china due to its cheap labour. That coupled with eliminating bureaucratic hurdles due to their monotononous political system and one party system, lets take an example of musharraf who was essentially a dictator but he took some decisions which in usual multi cultural society and democratic environment would have seen lots of obstacles, but musharraf implemented his policies with total control and no democratic procedure, the good policies like local government etc which was overturned shortly after the restoration of democracy or whatever, when one man was not making decisions, the implementation of policies became much harder.
china's one party policy may bite back hard as seen in hongkong unrest and uigher unrest, one also needs to observe the side effects of one party system, elimination of diversity and implementation of monotonous rule of one party all across the mammoth country. It even has one time, the far flung western areas have to follow the time of predominantly han chinese areas in the far east. So the ''miracle of the world history'' also needs to be elaborated with the kind of political system being followed in china.
A liberal economy with a very non liberal and close minded government, is a contradiction which china will have to face sooner than later.
Also notice the 40 year period stated by the guy rather than 70 year economic period stated by the poster else where.
regards