Every economic regulation–whether laws governing labor, product quality, or prices of goods or services–creates a black market. And socialist countries which seek to regulate everything suffer (or, rather, experience the comforts and joys of) black markets in every commodity and industry.
Here is a recent BBC story about efforts to thwart free-market transactions in Venezuela–a land of great natural riches which has made itself poorer by years of socialist election victories.
The government of Venezuela is now posting military troops at traffic corridors and border points–and otherwise imposing martial law–to fight “smugglers.”
And, as the BBC reports, the poorest among Venezuelans are suffering most.