Why were there always shortages of consumer goods in the former soviet union?
The USSR spent about 70% of their economy's total GDP on the military. Because of this they had nationwide shortages which resulted in its collapse in 1991.
Command economies as in the former Soviet Union often have terrible shortages of common consumer goods like bathroom tissue How do market economies usually avoid such terrible shortages?
The economic policies of the former Soviet Union were a major failure which is just one of the reasons the Soviet Union no longer exists. Consumer goods were 2nd to Defense projects and Space exploration. Finally the leaders of the USSR realized that centralized economic planning simply cannot work. Freer economies have their faults but few can compare to the dismal performance of "communist" economics.