This paper studies the effects of risk aversion and density of contribution (DoC) on comparisons of proportional charges on flow (contributions) and balance (assets) during the accumulation phase of a defined-contribution pension plan in a system of individual retirement accounts. If the participant's degree of risk aversion increases and both charges yield the same expected terminal wealth, then the charge on balance improves with respect to the charge on flow when performing comparisons that examine the ratio between the resulting expected utilities of terminal wealth. When this methodology is applied to the Peruvian Private Pension System, empirical results demonstrate that the aforementioned result also holds for arbitrary charges on flow and balance and that the effect of DoC on these comparisons is nearly negligible for most of the assessed scenarios.