The institutional instability that the lack of a clear and easily understood system for the transfer of power led to helped to hasten the demise of the Soviet system. Of course, Gosplan probably did its fair share, and ultimately the greed of the people at the top led them to take the system down from above. Why hide money in Swiss banks and hope the KGB doesn't reveal what it knows about your money if you can take down the system and just own that money outright with no fear?

I mostly agree with Don Raleigh's points but had the opportunity to have some very interesting debates with him on the subject as I'm not in 100% agreement (he was my Soviet history professor in college - in fact, he urged me on multiple occasions, once with another professor, to become a Russian historian; in retrospect, I probably should have done it).