A California entrepreneur is warning of a "giant sucking sound" of business leaders leaving the state if voters approve a proposed billionaire wealth tax. Proposition 40 would impose a one-time 5% tax on the net worth of billionaires who were California residents on Jan. 1, 2026, with 90% of the revenue designated for public health care services. Eric Schiffer argues the measure could push entrepreneurs, jobs and investment elsewhere. California's nonpartisan Legislative Analyst's Office says some billionaires may leave, estimating the tax could generate tens of billions of dollars temporarily while potentially reducing annual state income tax revenue by less than $1 billion. The measure goes before California voters on Nov. 3.