世界银行-简化税制设计中的权衡：来自撒哈拉以南非洲的证据（英）-2024.9-54页_2mb

Simplified Tax Regimes: Balancing Revenue, Simplicity, and Equity Trade-offs

1. Key Insights on Design Features

• Eligibility Thresholds: Minimum thresholds (e.g., income thresholds) are inconsistently applied, with 60% of African countries not requiring one (KRA Kenya example). This leads to high compliance costs for very small businesses.
• Tax Calculation Method: Most countries use turnover-based percentages (70%), but 30% rely on fixed fees or combinations. Fixed fees are simpler but regressive, while percentage-based systems increase complexity.
• Tax Obligation Size: Profitability-linked thresholds vary widely (2–20%). High rates discourage formalization, but low rates incentivize tax evasion among larger enterprises.

2. Sub-Saharan African Context

• Adoption and Variation: Two-thirds of countries (2024 March) use simplified tax regimes (STRs), but 40% lack minimum thresholds, and taxable rates range from 1% to 4%.
• Country-Specific Shortcomings: Kenya’s turnover tax (TOT) allows businesses below the threshold to declare taxes, exacerbating informalization. Taxpayers often misreport turnover in response to tax rate hikes, offsetting revenue gains.

3. Behavioral Response Limitations

• Exemption Non-Compliance: Small businesses frequently declare incomes too high to exploit exemptions, driven by inadequate knowledge or fear of audit (40% unregistered).
• Tax Evasion: A 3% tax hike in Kenya caused a 25% average revenue drop as firms reduced declared turnover.

4. Randomized Experiment: Fixed Fees Pilot
Encouraging fixed fees based on business type and location increased average collections by 19.8% but disproportionately affected smaller firms, reducing equity.

Conclusion: STRs face significant trade-offs. While designs vary across Africa, policymakers struggle to balance revenue, simplicity, and equity. Fixed fees improve efficiency but worsen fairness, and awareness campaigns are needed. Future experiments and cross-country analyses are recommended to optimize tax policy.