This paper shows by means of the concept of utility that annuitization through life annui-ties or a pension can be an efficient instrument for the economic assurance of seniors. Various quantitative arguments are presented supporting this statement (e.g. annuity equivalent wealth [AEW] is calculated using Czech data). In conclusion, some practical arguments are mentioned regarding why the real demand on life annuities contradicts this result so that a so-called annuity puzzle arises in pension practice.