It has not been proven inefficient. In fact quite the opposite. A Good regulatory invironment coralates well with economic freedom and national per capita wealth.
Just look as Haratiges Most free nations. Those nations with a soled set of regulations and institutions generate the most economic activity. Those with out the regulatory framework and institutional structures to promote free markets produce the least economic activity.
In no case is minimal government involvment inthe market coralated with economic prosperity.