Besteuerung von Aktienoptionsprogrammen für Mitarbeiter bei Einkommensteuerprogression

Abstract

This paper investigates the effects of taxes on the optimal timing of the taxation of stock option compensation for managers and employees. It is shown that the taxation of the fair market value at grant can be both advantageous or disadvantageous for managers and employees compared to the taxation of realized gains at exercise. Results are heavily dependent on assumed risk preferences and tax progression. In most instances, risk averse actors would prefer the taxation of realized gains at exercise. Another result is that taxation of the fair market value at grant tends to reduce the holding period leading to rational early exercise by risk averse actors. Since this behaviour tends to reduce option value, taxation of fair market value based on time to maturity instead of time to exercise can lead to extremely high real tax rates which may exceed 100%. This result suggests that taxation of realized gains is more appropriate since problems of measuring individual risk preferences or applying an unduly high real tax rate are avoided. Furthermore, at grant taxation may result in employees reluctant to take part in stock option plans. Therefore, a tax system with at grant taxation is more likely to affect behaviour adversely than is a system with an exercise tax.