Methodology

Data Sources

Employment, earnings, population, and business data accessed via Nomis (nomisweb.co.uk). House prices from HM Land Registry linked data (landregistry.data.gov.uk). Business demography from ONS published tables.

Location Quotients

A location quotient (LQ) measures the relative concentration of an industry in a local area compared to a reference economy (England).

Shift-Share Analysis

Shift-share decomposes employment change in each sector into three components:

Validation: For every sector, the three components sum exactly to the actual employment change. This is a mathematical identity, not an approximation.

House Prices

Median house prices are sourced from the HM Land Registry Price Paid dataset via their SPARQL linked data endpoint. We use December average prices for each year (2015 onwards) to provide consistent annual snapshots.

The price-to-earnings ratio divides the median house price by median annual workplace earnings (from ASHE) for the same local authority. Year-on-year change is calculated from the two most recent December figures available.

Population Estimates

Mid-year population estimates are the official measure of population between Censuses, published annually by ONS. They are based on the most recent Census, updated for births, deaths, and migration.

Age profile shows the percentage of the population in three broad groups: under 16, working age (16-64), and 65 and over. Population change is calculated over the five most recent available years.

These estimates are more current than Census 2021 data and provide the denominator for per-capita calculations (e.g., enterprises per 1,000 population).

Gender Pay Gap

The gender pay gap is calculated as: (male median - female median) / male median, using ASHE workplace-based estimates. This measures the difference in median annual gross earnings between men and women working in the same local authority area.

Values may be suppressed for areas with fewer than 30 respondents in either the male or female sample. Full-time and part-time medians are also sourced from ASHE (all workers, not split by gender).

Business Demography

Enterprise births and deaths are sourced from the ONS Business Demography publication. A birth is a new enterprise appearing on the Inter-Departmental Business Register (IDBR). A death is an enterprise that has ceased to trade.

The birth rate is calculated as: births / active enterprises. Net formation rate is: birth rate - death rate. Survival rates track the percentage of enterprises born in a given year that remain active after 1, 3, and 5 years.

Note: Business Demography covers VAT and/or PAYE registered enterprises only. Self-employed individuals below the VAT threshold are excluded.

Business Environment

Enterprise counts come from the UK Business Counts dataset on Nomis, which is derived from the Inter-Departmental Business Register (IDBR). This covers VAT and/or PAYE registered businesses.

Size bands follow the standard classification: micro (0-9 employees), small (10-49), medium (50-249), and large (250+). The three-year trend shows net change in total active enterprises, and the growth rate is calculated from the earliest to the latest available year.

Interactive Map

The homepage choropleth map uses Local Authority District boundaries from the ONS Open Geography Portal (December 2023 vintage, super-generalised and clipped to the coastline). Boundaries are rendered as SVG using react-simple-maps.

Colour scales use the 5th and 95th percentile of each metric to set the range, preventing extreme outliers from compressing the visible variation.

Impact Multipliers

The impact calculator uses Type I input-output multipliers to estimate the indirect (supply chain) effects of investment or job creation in a local area. These are indicative estimates, not formal impact assessments.

Method

Limitations and caveats

• Type I only. These multipliers capture indirect (supply chain) effects but not induced effects (additional household spending from wages). Type II multipliers, which include induced effects, would be larger.
• SLQ is a simplification. More sophisticated methods (CILQ, FLQ, augmented FLQ) exist but require additional data. SLQ tends to overestimate regional self-sufficiency for large sectors and underestimate it for small ones.
• National coefficients applied locally. Production technology is assumed to be the same nationally. In reality, local firms may use different input mixes.
• Static model. Input-output analysis assumes fixed proportions. It does not account for price changes, capacity constraints, or behavioural responses.
• 19-sector aggregation. Multipliers are computed at the SIC section level (19 sectors). More granular analysis would use division or class-level data.

Limitations

• BRES employment figures are rounded to the nearest 100 by ONS for disclosure control. Small sectors may have proportionally large rounding effects.
• ASHE earnings data may be suppressed for small areas or sectors with fewer than 30 respondents.
• Census 2021 data reflects a single point in time (March 2021) during the COVID-19 pandemic. Occupation and qualification distributions may have shifted since.
• House prices are December annual averages from HM Land Registry. They may differ from UKHPI or other published indices which use different methodologies.
• Business counts cover only VAT/PAYE registered enterprises. Self-employed individuals below the VAT threshold are excluded.
• Some local authority boundaries were merged between 2019 and 2023. A small number of abolished districts may appear without data on the map.
• Location quotients are sensitive to the reference economy chosen. We use England as the benchmark throughout.
• Coverage spans 391 local authorities across England, Wales, and Scotland. Northern Ireland is not yet included.