Benford's law — methodology

This page explains why the Benford test exists, why we prefer the second-digit test (2BL) to the first-digit test for election data, what thresholds we apply, and how MAD and χ² should be read. The goal is to make transparent both what the test can and cannot say.

What you'll find

  • Why the first-digit test often shows "deviation" on clean electoral data.
  • Why 2BL (second digit) is preferred — Mebane's line of work.
  • Thresholds: minimum 10 votes per section, minimum 30 sections per party.
  • MAD bands: Close to Benford / Moderate / Strong deviation.

For the live screen see Benford's law by party.

Explore the data

  • Home
  • Governance
  • National Assembly
  • Roll-call votes
  • Governments
  • MP business connections
  • Public procurement
  • State budget
  • EU funds
  • Indicators
  • Consumption
  • Prices
  • Party financing
  • Opinion polls
  • Seat simulator
  • Parties
  • Results by region
  • Extraordinary local elections
  • Local-elections reconciliation
  • Sofia
  • About the project

Recent analysis

  • Budget 2026: adopted in month seven — what the numbers show
  • Machine-only voting: who wins and who loses
  • Budget 2026 in focus: the record deficit, the critics, and a check against the numbers