Prioritized Interventions

Within the four-pillar strategy from Core Strategy, not all interventions are equally promising. This page ranks the eight interventions surveyed in Section 2 against four criteria: effect size (how much it moves the top wealth share), evidence quality (how confident we can be in that estimate), political tractability (likelihood of enactment over a 5–10 year horizon), and reversibility risk (how easily a successor government can roll it back).

The top-ranked interventions are those that score well on multiple dimensions and that unlock other interventions. Beneficial-ownership transparency is the highest-ranked because it is a precondition for effective taxation of the top — without it, every other lever leaks through offshore. Inheritance taxation is second because it has the strongest evidence-to-effect ratio, with long-run elasticities of 0.1–0.2 (Kopczuk 2013, NBER WP 15741) — among the lowest of any tax instrument. Sectoral bargaining is third because it has high effect, durable institutional form, and a track record across multiple advanced economies.

The lowest-ranked are not unimportant but face severe constraints. Net wealth taxes have a poor empirical track record despite strong theoretical appeal — most European countries that adopted them have since abolished them, with behavioral elasticities roughly 3–4× higher than for estate taxes (Jakobsen, Jakobsen, Kleven & Zucman 2020, QJE). Supreme Court reform in the U.S. would unlock democratic reforms but has near-zero short-run feasibility. UBI has strong effects on poverty but a much weaker direct effect on top-end concentration than its political profile suggests.

Combined ranking

Rank	Intervention	Effect	Evidence	Tractability	Reversibility
1	Beneficial-ownership transparency	High	High	High	Low risk
2	Inheritance / estate taxation	High	High	Medium	Medium
3	Sectoral bargaining	High	High	Medium	Low risk
4	Global minimum corporate tax (Pillar Two)	Medium	Medium	High	Low risk
5	Antitrust (merger enforcement + monopsony)	Medium	Medium	Medium	Medium
6	Capital gains at ordinary rates	Medium	High	Medium	High risk
7	Public campaign financing	Medium	Medium	Medium	Medium
8	Baby bonds / asset endowments	Medium	Low	Medium	Medium
9	Billionaire minimum tax (Zucman)	High	Low	Low	High risk
10	UBI (universal, large)	Low–medium	Medium	Low	Medium
11	Net wealth tax (annual, broad)	High	Low	Low	High risk
12	Structural breakup of dominant firms	High	Medium	Low	Low risk

Sources: Effect-size and evidence ratings draw on empirical literature surveyed in Progressive Taxation, Antitrust and Competition, Labor Power, and Global Tax Coordination. Tractability and reversibility ratings reflect conditions as of 2025–26.

Methodology: how the ranking was constructed

The combined ranking is the product of four scores per intervention:

Effect size: Best estimate of the intervention’s effect on the top 1% wealth share, holding other interventions constant. Drawn from the empirical literature surveyed in Section 2; expressed as Low / Medium / High.
Evidence quality: Confidence in the effect-size estimate. High = multiple credible quasi-experimental or RCT studies with consistent results; Medium = several cross-country observational studies or single high-quality study; Low = theoretical or mechanism arguments without strong empirical basis.
Tractability: Probability of substantive enactment within 5–10 years given current political conditions. High = enacted in some major jurisdiction or near-enactment; Medium = active legislative or institutional momentum; Low = no current legislative path.
Reversibility risk: Probability that a hostile successor government could undo the intervention within 5 years. Low risk = institutional or international architecture makes rollback costly; Medium = standard legislative reversal; High risk = simple administrative reversal or constitutional vulnerability.

The four scores combine multiplicatively rather than additively. An intervention with very high effect size but very low tractability scores worse than one with medium effect and medium tractability, because the expected value over a 10-year horizon is what matters and zero probability of enactment kills the math regardless of effect size.

Two important caveats:

The ranking is opinionated. Reasonable analysts will weight the four criteria differently — a more risk-tolerant analyst will rank ambitious-but-fragile interventions higher; a more institutionally-conservative analyst will rank durable-but-modest interventions higher. The ranking here weights all four roughly equally, which produces a moderate-incrementalist bias.
The ranking is U.S.-centric. Country-specific rankings differ substantially (see below).

Why beneficial-ownership transparency ranks first

Beneficial-ownership transparency is structurally different from every other intervention on the list because it is a precondition rather than a substantive policy. It does not directly tax wealth, redistribute income, or build power. What it does is make wealth visible — which then makes every other intervention on the list more enforceable and less elastically avoidable.

The empirical record demonstrates this directly. The 2017–2018 Common Reporting Standard implementation produced roughly a 14% drop in offshore deposits in early-adopting jurisdictions (Casi, Spengel & Stage 2020, Journal of Public Economics) — not because the CRS itself imposed any tax, but because the visibility it created made existing taxes effective on a base that had previously been hidden. The same dynamic operates for every other intervention: a wealth tax with comprehensive beneficial-ownership infrastructure is meaningfully more effective than the same wealth tax without it; a corporate minimum tax with international information exchange is more effective than the same minimum tax without it; an antitrust regime that can identify ultimate beneficial owners of monopolistic firms is more effective than one that cannot.

The political-economy case is also strong. Transparency reforms have unusually broad support — they are favored by tax administrations, financial regulators, anti-corruption institutions, journalists, and most center-of-the-spectrum voters — and unusually weak organized opposition (the wealth-management industry opposes, but cannot mobilize broader publics against transparency). The 2022 U.K. Register of Overseas Entities passed the U.K. Parliament in two weeks under the Economic Crime (Transparency and Enforcement) Act, an extraordinary political velocity for a substantive financial-transparency reform, after Russia’s invasion of Ukraine made the politics impossible to oppose.

The cost is also low. Building a beneficial-ownership registry costs millions to tens of millions per jurisdiction; the revenue and enforcement gains are in the billions per year. The benefit-cost ratio is among the most favorable in the policy literature.

For all these reasons — structural leverage, empirical track record, political feasibility, low cost — beneficial-ownership transparency outranks interventions that are more substantively important in raw terms (a wealth tax raises more revenue than a registry does) but that depend on the registry to operate effectively.

The high-effect / high-resistance tradeoff

The dominant pattern in the ranking table is that interventions with the largest direct effects on top-end concentration also face the highest political resistance. Wealth taxes (effect size: high; tractability: low) and structural antitrust breakups (effect: high; tractability: low) sit at one end. Beneficial-ownership transparency (effect: high as enabler; tractability: high) sits at the other.

This is not coincidence. Concentrated wealth has the political resources to mobilize against any intervention that threatens its position; the more direct the threat, the more resources are mobilized. Interventions that are technocratic, indirect, or framed as anti-corruption / good-governance attract less mobilized opposition than interventions that are framed as redistribution.

The strategic implication is that the optimal sequencing is not “do the highest-effect interventions first” but rather “do the interventions that build the political and institutional infrastructure for higher-effect interventions later.” Beneficial-ownership transparency, Pillar Two corporate minimums, and antitrust enforcement at existing agencies all fit this profile: they are not the most ambitious interventions on the list, but they (a) enacted in 2024–2026, (b) have demonstrated empirical success, (c) build the constituencies and capacities for more ambitious follow-on action.

The risk of this incrementalist sequencing is that the “later” higher-effect interventions never come — political conditions never align, the early-stage gains get rolled back before the next stage advances, the entire trajectory plateaus at modest tinkering. This is the legitimate critique of incremental approaches and the case for movement strategies that try to advance multiple tiers simultaneously rather than sequentially. The honest answer is that the empirical record on incrementalism vs. transformative strategy is genuinely mixed, with success and failure cases for both approaches.

Country-specific re-rankings

The ranking above is U.S.-centric. The same interventions re-rank substantially in other jurisdictions because the political-feasibility and reversibility scores are country-specific.

EU: The Pillar Two minimum corporate tax has already been enacted (effective 2024), raising its expected value contribution. Sectoral bargaining is already extensive, raising its tractability for further extension. The billionaire minimum tax has stronger political support (Spain, France championing; championed by Brazil’s 2024 G20 presidency). Wealth taxes have a longer track record (Spain, Norway, Switzerland) and higher tractability than in the U.S. The European re-ranking would push international coordination interventions (Pillar Two extensions, UN Tax Convention, billionaire minimum) substantially higher and would push U.S.-specific interventions (Citizens United reform, NLRB reform) lower.

Global South: The priority order shifts again. Beneficial-ownership transparency is even more important (because Global South countries are net losers from offshore wealth flows — see Global Wealth Concentration on offshore measurement). Global tax coordination via the UN Convention is the highest-priority intervention because it shifts rule-writing toward more representative venues. Domestic interventions (progressive taxation, antitrust) have similar relative rankings to the U.S. but face stronger state-capacity constraints.

Specific country sub-rankings: The U.K. priority list emphasizes lobbying-disclosure expansion, council-tax reform, and beneficial-ownership transparency. Brazil emphasizes domestic wealth taxation and global coordination. India emphasizes antitrust enforcement and progressive income taxation. The pattern is that the top of every country’s list contains interventions specifically tailored to that country’s binding constraints.

How this informs Section 4

The ranking has direct implications for which organizations and movements are most leverageable.

Research and Policy Institutes — the highest-leverage institutes are those producing the technical infrastructure for Tier 1 interventions: WID for measurement, EU Tax Observatory and TJN for transparency and coordination, Roosevelt and the Open Markets Institute for antitrust. The institutes producing Tier 3 work (wealth-tax design, billionaire minimums, court reform) are valuable but operate on a longer payoff horizon.

Advocacy and Campaign Organizations — the most operationally important advocacy organizations are those running Tier 1 and Tier 2 campaigns: Tax Justice Network on transparency, Patriotic Millionaires on tax, Public Citizen on antitrust, Americans for Tax Fairness on the federal tax agenda. The Davos-cycle organizations (Oxfam) operate at a different layer (narrative-and-agenda-setting) that supports rather than substitutes for substantive campaigns.

International Institutions — the OECD/G20 Inclusive Framework is the most consequential single institution because it is currently the operational venue for Tier 1 international interventions. The UN Tax Convention process is the most consequential future institution because it could shift the venue of rule-writing for the next generation of interventions.

Grassroots Movements — the highest-leverage grassroots organizations are those building durable constituencies for Tier 2 and Tier 3 interventions: sectoral unions, tenant unions, employee-ownership federations. These organizations supply the political base that converts research and advocacy into enacted policy.

The ranking is not static. Successful Tier 1 wins (e.g., consolidation of beneficial-ownership infrastructure, durable Pillar Two enforcement) will reshape the ranking by moving Tier 2 interventions higher in tractability. The ranking is most usefully read as a snapshot of priorities under current conditions rather than as a fixed prescription.