UK Government Debt (% GDP)
UK debt-to-GDP rose from ~25% in 1913 to over 130% by 1919 — the most dramatic fiscal transformation of the war.
155.0%
Trend YoY growth is -7.4%, slowing by 4.3 pp/year over the last 5Y. Latest: -5.0%, 2.4 pp above trend, a 0.2σ deviation. The latest YoY reading is boosted by 1.9 pp due to an easy comparison base from 1924.
Level
YoY Change
y = 14.0% − 4.3 pp/yr · t
Deviation from trend
Forecast
Projected value by forecast vintage (%)
Projected value (%)
| Forecast made in | 1918 | 1919 | 1920 | 1921 | 1922 | 1923 | 1924 | 1925 | 1926 | 1927 | 1928 | 1929 | MAPE |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1918 | 125.0 | 154.0 | 167.0 | 165.0 | 213.0 | 211.0 | 209.0 | 207.0 | 205.0 | 258.0 | 313.9 | 372.9 | 679% |
| 1919 | 135.0 | 145.5 | 137.0 | 178.5 | 170.0 | 161.5 | 153.0 | 144.5 | 130.5 | 113.0 | 92.0 | 122% | |
| 1920 | 130.0 | 122.5 | 160.0 | 147.5 | 135.0 | 122.5 | 110.0 | 57.5 | -2.5 | -70.0 | 363% | ||
| 1921 | 175.0 | 198.5 | 195.0 | 191.5 | 188.0 | 184.6 | 215.6 | 248.2 | 282.2 | 615% | |||
| 1922 | 170.0 | 178.5 | 172.0 | 165.5 | 159.0 | 161.6 | 162.6 | 162.2 | 240% | ||||
| 1923 | 165.0 | 164.0 | 156.0 | 148.0 | 138.1 | 125.1 | 109.2 | 50% | |||||
| 1924 | 160.0 | 150.0 | 140.0 | 120.0 | 95.1 | 65.1 | 100% | ||||||
| 1925 | 155.0 | 130.0 | 95.0 | 50.0 | -5.0 | ||||||||
| 1926 | 130.0 | 95.0 | 50.0 | -5.0 |
YoY change forecast
| Forecast made in | 1918 | 1919 | 1920 | 1921 | 1922 | 1923 | 1924 | 1925 | 1926 | 1927 | 1928 | 1929 | MAPE |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1918 | +20.0% | +29.0% | +32.0% | +35.0% | +38.0% | +41.0% | +44.0% | +47.0% | +50.0% | +53.0% | +56.0% | +59.0% | 679% |
| 1919 | +10.0% | +10.5% | +7.0% | +3.5% | +0.0% | -3.5% | -7.0% | -10.5% | -14.0% | -17.5% | -21.0% | 122% | |
| 1920 | -5.0% | -7.5% | -15.0% | -22.5% | -30.0% | -37.5% | -45.0% | -52.5% | -60.0% | -67.5% | 363% | ||
| 1921 | +45.0% | +23.5% | +25.0% | +26.5% | +28.0% | +29.5% | +31.1% | +32.6% | +34.1% | 615% | |||
| 1922 | -5.0% | +8.5% | +7.0% | +5.5% | +4.0% | +2.5% | +1.0% | -0.5% | 240% | ||||
| 1923 | -5.0% | -1.0% | -4.0% | -7.0% | -10.0% | -13.0% | -16.0% | 50% | |||||
| 1924 | -5.0% | -10.0% | -15.0% | -20.0% | -25.0% | -30.0% | 100% | ||||||
| 1925 | -5.0% | -25.0% | -35.0% | -45.0% | -55.0% | ||||||||
| 1926 | -25.0% | -35.0% | -45.0% | -55.0% |
Forecasts use ordinary least-squares linear regression fitted to the YoY change series over a rolling 5Y window. Each row shows a vintage — the forecast as it would have appeared at that point in time. Projected values apply the forecasted YoY change to the prior year's level, chaining forward where actuals are unavailable. MAPE measures forecast accuracy against realized values. These are mechanical trend extrapolations, not economic models.