"This Is Why There Is No Toilet Paper in Venezuela"
http://transitions.foreignpolicy.com/posts/2013/06/17/this_i...
The problems of the local toilet paper industry are illustrative. Typical of the global supply chain, many inputs that manufacturers need to produce toilet paper are also imported. But since Venezuela has extensive currency exchange controls to regulate the flow of foreign currency (which can either be bought/sold or obtained through trade), the government must approve all imports -- and the red tape involved is legendary.
In theory, the way the Venezuelan system should work is the following: The government authorizes imports by selling dollars that businesses buy to make international purchases at a heavily-subsidized price -- discounted at a much lower price than what the black market sells it for. After the imports have arrived and have cleared customs (lines at ill-equipped Venezuelan ports can last weeks), local manufacturers produce their goods, and then sell their products at tightly-controlled prices.
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In reality, the government's ineffective regulation not only discourages investment, but creates incentives for people in the chain of production to take advantage of access to cheap dollars and sell them in the highly profitable black market. With "import dollars" reallocated to currency arbitrage, there is little money left to import the raw materials needed to make things that Venezuelans need.