The holes in 15 years of 509 tuition data, and how we patched them

The ABA Standard 509 disclosures are the best public record of what law school costs, but in places they are wrong, not from bad faith but from fifteen years of spreadsheets kept by two hundred schools. Exhibit reconciles every tuition cell against a master workbook; this is the field guide to the recurring errors and what we do about each.

The apostrophe that ate the tuition

A single leading apostrophe in a source cell (Excel's treat-this-as-text marker) makes a number fail to parse, so it lands as $0 or a truncated fragment. Where a trustworthy figure exists we recover it; where it does not, we show an open circle, a visible not-reported, instead of a fake near-zero.

The per-term trap

Around 2018 the ABA began reporting tuition by the term rather than as a flat annual sticker. Read literally, a chart shows tuition halving overnight; the number just switched units. We convert everything to a single annual figure so the line stays smooth where a raw plot zig-zags.

Doubles and halves

Some cells are entered at twice or half the real number. These are the easy ones: the years on either side bracket the truth, and the school's own per-credit rate confirms it.

The thing that looks wrong but is not

At a public school you will sometimes see a median scholarship larger than resident tuition. That is not an error: the ABA reports grants school-wide, pooling residents and non-residents, and scholarships are scaled to the higher non-resident sticker.

What we actually do

We do not quietly rewrite history. Every adjudicated value is drawn on the chart as a small amber ring with a hover note, and logged cell by cell in a public corrections ledger. The raw layer keeps the original ABA figure, so every edit is reversible.