Havens are places where you can put your wealth in order to escape the rules at home. Those rules might be around tax, or criminal laws, or rules about transparency and disclosure, or financial regulations. (...) They also help multinationas outcompete their smaller and more local competitors. Tax havens aren’t the only reason your local bookstore has gone out of business – but they are a big part of it. (Note, too, that these are not “leftist” concerns. Tax havens are tilting the playing field for business: people across the political spectrum should oppose this. To be anti-tax haven is, in a very profound sense, to be pro-business.) 
Tax havens are (...) places that help [the Rich people] cream off the benefits of society – roads, hospitals, educated workforces, courts and contracts and so on – while shaking off the costs, risks and responsibilities: the taxes, the disclosure rules, the criminal laws and more. (...) Most worrying is how hard the world has found it to crack down on such places. Leaders at a G20 summit in 2009 declared "the era of banking secrecy is over" (...) but the overall result looks more like a whitewash. (...) Why do we still tolerate these offshore bolt holes? The answer: because our wealthiest and most powerful élites want them. In this age of austerity, we need a better reason.