computed-weighted-domain-bands

Date: 2026-10-01. Status: implemented.

Decision. Both tables carry a computed population-weighted Scotland quintile and decile of every domain rank, simd_domain_pw_scotland, 82 columns, and each edition's data-zone population, simdpopulation, 6 columns: schemas postcode_simd_wide_v5 (442) and postcode_simd_sspl_v5 (399). The one exception to bands-are-looked-up: nobody publishes these. They are cut per data zone in the Government reader, every zone of the edition once with that edition's shapefile population, never from a postcode table: zones ordered by rank, equal ranks one block, band = max(1, min(k, ceil(midpoint * k / total))). Before any is used, the same rule must reproduce PHS's published overall Scotland quintile and decile exactly in every edition, or the build stops. Labelled "computed population-weighted band, using a midpoint rule validated against PHS's published overall bands; equal ranks grouped together; not published by PHS or the Government". SQL measures computed_pwdomain; the walkthrough carries the decile beside the published one. Scotland only; no sub-geography bands, flags or vigintiles. Released as 6.0.0.

Reason. Analysts ask for population-weighted domain bands, and official guidance recommends the income domain alone, or SIMD without health, for health outcomes; the Scottish Government's income-employment index and Bradford et al. (Health & Place, 2023) cut population-based bands of domain measures. Checking the rule against PHS on every build is what makes a computed band defensible. PHS is to be asked whether it has a view; the attribution stays "computed" unless it does.

Evidence. The rule reproduces PHS's published Scotland quintile and decile on every zone of all six editions; within health boards, HSCPs and councils it does not, mostly in the island areas, so none are produced. Every computed band holds its fifth or tenth of the population to within 0.036 percentage points. Cutting from the main table's zones instead would drop four 2011 zones (801 people in 2017) and change five 2020v2 income deciles. The 354 history and 311 main columns of 5.0.0 keep their fingerprints. Plan: docs/plans/Weighted_Domain_Bands_Plan.md.

Columns (88): simd2004_access_domain_pw_scotland_decile, simd2004_access_domain_pw_scotland_quintile, simd2004_education_domain_pw_scotland_decile, simd2004_education_domain_pw_scotland_quintile, simd2004_employment_domain_pw_scotland_decile, simd2004_employment_domain_pw_scotland_quintile, simd2004_health_domain_pw_scotland_decile, simd2004_health_domain_pw_scotland_quintile, simd2004_housing_domain_pw_scotland_decile, simd2004_housing_domain_pw_scotland_quintile, simd2004_income_domain_pw_scotland_decile, simd2004_income_domain_pw_scotland_quintile, simd2004_population, simd2006_access_domain_pw_scotland_decile, simd2006_access_domain_pw_scotland_quintile, simd2006_crime_domain_pw_scotland_decile, simd2006_crime_domain_pw_scotland_quintile, simd2006_education_domain_pw_scotland_decile, simd2006_education_domain_pw_scotland_quintile, simd2006_employment_domain_pw_scotland_decile, simd2006_employment_domain_pw_scotland_quintile, simd2006_health_domain_pw_scotland_decile, simd2006_health_domain_pw_scotland_quintile, simd2006_housing_domain_pw_scotland_decile, simd2006_housing_domain_pw_scotland_quintile, simd2006_income_domain_pw_scotland_decile, simd2006_income_domain_pw_scotland_quintile, simd2006_population, simd2009v2_access_domain_pw_scotland_decile, simd2009v2_access_domain_pw_scotland_quintile, simd2009v2_crime_domain_pw_scotland_decile, simd2009v2_crime_domain_pw_scotland_quintile, simd2009v2_education_domain_pw_scotland_decile, simd2009v2_education_domain_pw_scotland_quintile, simd2009v2_employment_domain_pw_scotland_decile, simd2009v2_employment_domain_pw_scotland_quintile, simd2009v2_health_domain_pw_scotland_decile, simd2009v2_health_domain_pw_scotland_quintile, simd2009v2_housing_domain_pw_scotland_decile, simd2009v2_housing_domain_pw_scotland_quintile, simd2009v2_income_domain_pw_scotland_decile, simd2009v2_income_domain_pw_scotland_quintile, simd2009v2_population, simd2012_access_domain_pw_scotland_decile, simd2012_access_domain_pw_scotland_quintile, simd2012_crime_domain_pw_scotland_decile, simd2012_crime_domain_pw_scotland_quintile, simd2012_education_domain_pw_scotland_decile, simd2012_education_domain_pw_scotland_quintile, simd2012_employment_domain_pw_scotland_decile, simd2012_employment_domain_pw_scotland_quintile, simd2012_health_domain_pw_scotland_decile, simd2012_health_domain_pw_scotland_quintile, simd2012_housing_domain_pw_scotland_decile, simd2012_housing_domain_pw_scotland_quintile, simd2012_income_domain_pw_scotland_decile, simd2012_income_domain_pw_scotland_quintile, simd2012_population, simd2016_access_domain_pw_scotland_decile, simd2016_access_domain_pw_scotland_quintile, simd2016_crime_domain_pw_scotland_decile, simd2016_crime_domain_pw_scotland_quintile, simd2016_education_domain_pw_scotland_decile, simd2016_education_domain_pw_scotland_quintile, simd2016_employment_domain_pw_scotland_decile, simd2016_employment_domain_pw_scotland_quintile, simd2016_health_domain_pw_scotland_decile, simd2016_health_domain_pw_scotland_quintile, simd2016_housing_domain_pw_scotland_decile, simd2016_housing_domain_pw_scotland_quintile, simd2016_income_domain_pw_scotland_decile, simd2016_income_domain_pw_scotland_quintile, simd2016_population, simd2020v2_access_domain_pw_scotland_decile, simd2020v2_access_domain_pw_scotland_quintile, simd2020v2_crime_domain_pw_scotland_decile, simd2020v2_crime_domain_pw_scotland_quintile, simd2020v2_education_domain_pw_scotland_decile, simd2020v2_education_domain_pw_scotland_quintile, simd2020v2_employment_domain_pw_scotland_decile, simd2020v2_employment_domain_pw_scotland_quintile, simd2020v2_health_domain_pw_scotland_decile, simd2020v2_health_domain_pw_scotland_quintile, simd2020v2_housing_domain_pw_scotland_decile, simd2020v2_housing_domain_pw_scotland_quintile, simd2020v2_income_domain_pw_scotland_decile, simd2020v2_income_domain_pw_scotland_quintile, simd2020v2_population