http://www.dailyreckoning.com.au/markets-not-meddlers/2013/03/15/The brecha, or spread, between the government's 5-to-1 rate and the blue market's near-8-to-1 is not insignificant. Those who can deal in dollars, therefore, do. Gresham's Law:
'When a government compulsorily overvalues one type of money and undervalues another, the undervalued money will leave the country or disappear from circulation into hoards, while the overvalued money will flood into circulation.' (Wikipedia)
The phenomenon can also be seen with regards to that fringy cyber currency, bitcoin. A single coin goes for a little under $50. At the official rate, that's about 250 Argentine pesos, give or take a few notes. But the market demands 400 pesos per coin.
