UK Senior Cabinet Churn & Tenure Analysis

Generated: 2026-01-15 20:27:54

Data source: UK Parliament API via cabinet_ministers.csv

Analysis period: 1970 onwards (completed parliaments only)

Methodology: Senior Cabinet posts identified via classification rules (Secretaries of State, PM, Chancellor, etc.) in the House of Commons

Summary Statistics - Completed Parliaments (1970 onwards)

Coverage

Completed parliaments analyzed: 15

Senior posts tracked: 895

Unique individuals: 334

Tenure Statistics

Mean tenure: 455 days (15.2 months)

Median tenure: 387 days (12.9 months)

Range: 1 - 1835 days

Churn Rates

Mean churn: 10.9 per year

Median churn: 9.6 per year

Peak churn: Parliament 57 (20.8 per year)

1. Cabinet Churn Rate by Election Year (Completed Parliaments)

Shows the rate of turnover in senior Cabinet positions, normalized per year for completed parliaments only. Higher values indicate more frequent changes in senior posts. Colors indicate the ruling party: Conservative | Labour

2. Tenure Duration Distribution by Election Year (Completed Parliaments)

Box plots showing the distribution of how long individuals held senior Cabinet posts following each general election in completed parliaments. Solid line = median tenure, dashed line = mean tenure. The box shows the interquartile range (25th-75th percentile), and red dots are outliers. Bar colors indicate the ruling party: Conservative | Labour

Notes:

Excluded parliaments: Parliament 39 (February 1974, 224 days), Parliament 48 (May 2010, 13 days hung parliament), and the current parliament (2024 onwards, still in session). The first two represent unusual electoral circumstances that distort year-normalized churn metrics. The current parliament is excluded because it has not completed its full term, making comparative analysis inappropriate.
Media era markers indicate approximate technological shifts affecting political communication
Tenure calculations are per-parliament segments; individuals may serve across multiple parliaments