Guaranty of deposits is also objected to on the ground that it is a form of assessment insurance, is not actuarial, does not select risks, and suffers from a high concentration of risks. It is true that guaranty of deposits is a sort of assessment insurance, but it is without the defects of such insurance. If it were made compulsory on all banks, the danger of the survivor being burdened and uninsured would not apply; and if, under a voluntary plan, a withdrawing bank should be held to pay losses arising for, say, six months afterwards, and if the amount of the assessments were strictly limited, the above danger would be minimized. Besides, the risk, instead of increasing with the age of the insured bank, would normally decrease as the bank matures, becomes conservative, and accumulates a surplus. Bank failures do tend to concentrate in periods of depression and in industrial areas; there is not, and cannot be, the dispersion of risks among many banks of different types, particularly if the guaranty system applies to banks of a single state, nor can there be a classification and selection of risks and an adjustment of premium according to risks, when the system applies to all banks. The necessity of a strict supervision to reduce the banks to uniformity of risk is therefore evident, as is the necessity of a strict examination of the candidate bank before admitting it to the system.