a computer - based method for determining a set of equity - indexed crediting parameters e for a lifetime - income equity - indexed deposit product provided to a set of owners having a set of dates of birth b , a rider charge c , a lifetime income percentage scale l , a set of profitability requirements r , a principal amount p , and an account value a . the method can include the steps of : establishing the values of c , l , r , p , a and e at a time when said deposit product is purchased ; generating a set of yield curve and equity index scenarios consistent with valuation parameters ; setting a trial value e i for e ; calculating the observed distribution d of profitability ; comparing d with r ; and , computing a revised trial value e i + 1 for e , where the steps of establishing , generating , setting , calculating , comparing , and computing are performed by at least one general purpose computer .