As with all government intervention, price controls do not achieve what their originators think they will. Trying to maintain a supply of milk by putting a price control on it will cause shortages, which are the very situations the price manipulators said they wanted to avoid.
Rent control seems great to the snug renter, but it will assure that no new building or renovations will be undertaken by entrepreneurs. Shortages follow. Agricultural subsidies, quotas and price support loans function as regressive taxes upon the poor. Sugar cane price controls are among long-standing interventions in the market.
The fourth in a series of ten lectures, from Fundamentals of Economic Analysis: A Causal-Realist Approach.