Abstract
Even if the shadow economy is often forgotten in our societies, this informal business is nevertheless really present in our developed societies. Called shadow economy, black economy or underground economy, this unofficial business is living from as long as business has existed. According to the French economist Sédillot (2000) in his book 'histoire des marches noirs', the shadow economy was acting in china ten thousand years before Jesus Christ, in order to avoid the pressures made by the state. Nowadays Governments are dealing with this problem with a very high importance, considering that it could be in the future a cause of failure of lot of today's policies. Consequently, we can wonder to what extent our west European countries are suffering from the underground economy and how a government has to deal with this phenomenon? The main objectives of this paper is understanding through the available literature what is really shadow economy, why does it affect our societies and mostly and what are the consequences of such problem? In order to answer these questions, we will define first the underground economy before studying its impacts, and we will in the final part, emphasize on different ways to fight against this informal economy.
