Every English council must publish every payment it makes over £500 — the raw chequebook. This variable measures what fraction of a council's monthly spending goes to just its ten biggest suppliers. A very high share means the council's money — and its risk — is concentrated in a few hands: less competition on price, and a serious problem if one of those big contractors goes under.
| name | top10_supplier_share |
|---|---|
| dataset | 11-transparency-code-spend |
| kind | constructed |
| type | numeric |
| unit | proportion 0–1 |
| grain | council-month |
| role | feature |
| source | sum(top-10 supplier spend) / total_spend, from normalised supplier and amount_gbp |
| period | per council-month (or pooled months) |
| missingness | Requires prior schema normalisation and supplier-name cleaning; three-council sample only. Coverage exclusions (Sefton) and unstated VAT treatment make cross-council levels only roughly comparable. |
| score_note | More interpretable sibling of the HHI, carrying largely the same information. |
| peer_group | council class (district / county / unitary / metropolitan / London) — not yet scored on the leaderboard |
The share of a council-month's spend going to its ten largest suppliers. It is a robust, easily interpreted companion to the HHI: high values suggest dependence on a few contractors — a risk and negotiating-position signal, not itself waste. Like all supplier constructs it inherits supplier-name normalisation quality and each council's documented coverage exclusions.