The real economy needs developed and efficient financial markets. Therefore, the experience of the financial crisis shows the need to re-design the rules of financial market participants and thus the prudential rules. But precisely because of the economic importance of the financial sector there is a need for an upstream in-depth impact analysis of the new proposed regulations to allow for an accurate and safe procedure to keep unwanted side effects low. The new Basel III rules include three main topics that will be also subject to impact assessment: (a) changes in capital mix and the increase of minimum capital ratios; (b) introduction of a leverage ratio; (c) introduction of liquidity ratios (liquidity coverage ratio and net stable funding ratio). We would like to make a sort of preliminary debate of the above problems, understanding the environment in which Basel 3 will develop them.