The paper uses a single-period option-based model to analyze the net value of business income under uncertainty, focusing on the effects of tax asymmetries and observing the distinct features of individual and corporate forms of business organization. Its parameters include the income tax structure and corporate leverage. Results are illustrated on applications using 2007 data in the Czech Republic and Slovakia. Various asymmetries are identified and discussed, leading to a hypothesis on the incentive to incorporate, less pronounced under the Czech tax framework, which tends to favour the personal form for a range of businesses.