Does taxing unrealized gains help or hurt entrepreneurial risk-taking?
Core argument: Accrual-based capital gains taxation reduces founder ownership by ~25% at exit vs. realization-based taxation, yet increases positive payoff probability from.
This paper examines how taxing unrealized capital gains affects entrepreneurship, combining a dynamic career-choice model with new evidence on all U.S. venture capital backed startups. Figure 1a plots a histogram of the positive company exit values. The distribution spans several orders of magnitude and is relatively similar to a lognormal, but with a right skew and fatter right tail. A stylized model highlights a key trade-off: accrual-based capital gains taxes dilute successful founders by forcing additional share sales before exit, a well known concern, yet they also provide insurance through tax credits to founders whose ventures fail, an aspect often overlooked. Quantitatively, advance taxation substantially reduces founders' ownership at exit: average founder shares fall about 25% under accrual-based taxation relative to realization based taxation. At the same time, accrual taxation increases the fraction of entrepreneurs with positive payoffs from around 16% to nearly 47%. Embedding these outcomes in a career-choice framework shows that the insurance value of accrual taxation partly offsets dilution costs: less risk-averse founders favor realization-based taxes, while more risk averse ones prefer accrual-based taxes. The strength of this insurance channel depends on the highly skewed distribution of entrepreneurial payoffs and the design of loss provisions under accrual-based taxation.

