What are the rating agencies?

What are the rating agencies?
Formally, the research departments are: evaluate the companies that issue securities and bonds, that is their "robustness". Were born as a side activity on Wall Street and in London, more than fifty years ago. They, then, was an entirely legitimate, what would any law firm. But then came the financial liberalization, and the role of these agencies has changed over time. They themselves, in fact, have become the companies issuing securities. What's more, they draw - through the activities of security design, with the participation of talented mathematicians - and then put them on the market. But having a role in the evaluation of course affect the market price. It so happens that the role of rating agencies to become dangerously hybrid. But it could be worse: some of these agencies, for example, have placed first in the securities market doomed to failure, and then the other titles protected by those failures.It should be added that the rating agencies in Europe have a considerable force, since the debt of European countries was "desovranizzato", as they no longer run the country (monarch) that issues securities. Simplifying a little 'things, up to forty years ago worked like this: the debt of scales, say if Italy was represented by bonds issued to the Treasury. Those bonds were purchased by the Central Bank, in this case the Bank of Italy, who gave orders to the various banks to buy those securities (called "bond portfolio"). In this way the circle is closed, and a state could never fail. This mechanism has already started to ease with the liberalization. But the final blow came with the single currency, that is, with the Euro at the moment, in fact, all countries that have adopted the euro do not have a common treasury, and the European Central Bank itself has no function or politics or "material" (does not have enough reserves) to purchase securities issued by various national treasuries. So the circle never closes, and the debt of each country is very vulnerable on the market.