Every English council must publish every payment it makes over £500 — the raw chequebook. This variable checks whether the same supplier charges different councils very different prices for the same category of work. Wide gaps suggest some councils are negotiating poorly or buying badly — if your neighbour pays half what you do to the identical company, that is money on the table.
| name | price_dispersion_same_supplier |
|---|---|
| dataset | 11-transparency-code-spend |
| kind | constructed |
| type | numeric |
| unit | dimensionless (coefficient of variation) or GBP (IQR) |
| grain | council-month |
| role | feature |
| source | CV or IQR of amount_gbp per supplier per expense category, for suppliers matched by normalised name across >=2 councils |
| period | per council-month (or pooled months) |
| missingness | Depends entirely on cross-council supplier matching by normalised name (no shared supplier ID; only Gloucestershire has an often-blank company number); three-council sample only, so matched-supplier coverage is thin. Schema normalisation is a prerequisite. |
| score_note | Genuinely novel cross-council price screen, but thin coverage and no unit quantities. |
| peer_group | council class (district / county / unitary / metropolitan / London) — not yet scored on the leaderboard |
For suppliers appearing in two or more councils, the dispersion of per-transaction amounts within an expense category — a rough cross-council price signal. High dispersion may hint that councils pay different prices to the same vendor. It is weak without unit quantities (an invoice total is price × unknown volume), so treat it as a screening statistic, never a price index.