Abstract
The risk of diversification is a basic precept of the banking activity. A big part of the large banking failures was due, in a way or another, to a concentration of the credit risk. The banking controlling authorities have, at all times, strongly encouraged the banks placed under their jurisdiction to avoid the concentration of risks. This concentration can take several forms. Apart from the credit risk, it can comprise an over-exposure to the market risks or an excessive financing risk when a bank calls too exclusively upon a given compartment of the market to get resources. Certain forms of risk concentration do not lend themselves easily to an objective measurement, in spite of their considerable importance for the monitoring of such or such bank. Moreover, the fact that the banks are often specialized in a particular field can mean that the profitability of this type of activity is above the average, although the risk which they incur is also higher than the average if the external factors seem less favorable.
