Short answer: it depends on your goals and how the policy is designed.
Reasons to raise top rates
•Equity: A dollar is worth less to a millionaire than to a median earner, so shifting tax burden upward can reduce inequality at relatively low welfare cost.
•Revenue for public goods: Concentrated income/wealth means modest increases at the very top can raise meaningful revenue.
•Optimal-tax theory: With realistic behavioral responses, many models find room for somewhat higher top marginal rates on very high labor income without large efficiency losses.
•Fairness/neutrality: Closing preferential treatment of certain income (e.g., some capital gains preferences or loopholes) can level the playing field.
Reasons to be cautious
•Behavioral responses: High earners can change how, where, and when they realize income; capital income is especially mobile and tax-sensitive.
•Growth/innovation concerns: If poorly designed, higher rates can deter entrepreneurship, risk-taking, or drive talent/wealth abroad.
•Avoidance/complexity: The higher the headline rate, the bigger the payoff to gaming the base unless enforcement and base-broadening keep up.
•Revenue limits: Beyond some point, higher rates can yield little extra revenue and more distortions.
If you do raise them, design matters more than the headline rate
•Target very high effective incomes with surtaxes or minimum tax rules rather than broad hikes that catch upper-middle professionals.
•Broaden the base: limit or cap itemized deductions for top earners; tighten pass‑through rules; tax derivatives and shelters consistently.
•Align rates across forms of income at the top and reduce timing games: e.g., curbing step‑up in basis at death, limiting deferral, addressing carried interest; pair with strong enforcement.
•Coordinate internationally (information‑sharing, exit taxes, residency rules) to reduce offshore shifting.
•Consider alternatives or complements: stronger estate/inheritance taxation, land value/property tax improvements, or a broad consumption tax with rebates—often more efficient than very high income-tax rates.
So, should they? If your priority is reducing inequality and funding services with minimal harm to growth, a well-designed package that modestly raises effective tax rates on the very highest incomes/wealth—mainly via base‑broadening, closing preferences, and targeted surtaxes—can be justified. If your priority is maximizing investment and minimizing avoidance risks, you might favor keeping top rates near current levels while shifting toward broader consumption or property bases and expanding credits for low- and middle-income workers.
What’s your main goal—reducing inequality, raising revenue, or protecting growth—and which taxes are you thinking about (income, capital gains, estate, or a wealth tax)?