Active Interstate War Dyads
How many state-to-state war relationships were live in the system each year — captures WWII's geographic spread.
30.00dyads
Trend YoY growth is -41.5%, slowing by 30.9 pp/year over the last 5Y. Latest: -14.3%, 27.2 pp above trend, a 1.0σ deviation. The latest YoY reading is boosted by 2.0 pp due to an easy comparison base from 1944.
Level
YoY %
y = 113.2% − 30.9 pp/yr · t
Deviation from trend
Forecast
Projected value by forecast vintage (dyads)
Projected value (dyads)
| Forecast made in | 1939 | 1940 | 1941 | 1942 | 1943 | 1944 | 1945 | 1946 | 1947 | 1948 | 1949 | MAPE |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1939 | 8.00 | 30.67 | 90.06 | 234.5 | 308.1 | 340.1 | 338.6 | 325.2 | 3.9k | 51.4k | 737.8k | 5147% |
| 1940 | 18.00 | 52.02 | 124.1 | 152.9 | 160.6 | 153.7 | 143.0 | 735.0 | 4.1k | 23.9k | 2550% | |
| 1941 | 38.00 | 94.46 | 110.3 | 110.7 | 101.9 | 91.55 | 292.3 | 974.9 | 3.4k | 1945% | ||
| 1942 | 42.00 | 63.97 | 55.54 | 43.88 | 33.58 | 33.07 | 28.12 | 20.12 | 629% | |||
| 1943 | 40.00 | 17.83 | -0.43 | -14.08 | 13.04 | -18.04 | 33.22 | 476% | ||||
| 1944 | 35.00 | 9.99 | -3.15 | 1.56 | -1.38 | 1.76 | 400% | |||||
| 1945 | 30.00 | 10.76 | 0.92 | -0.17 | 0.08 | |||||||
| 1946 | 10.76 | 0.92 | -0.17 | 0.08 |
YoY change forecast
| Forecast made in | 1939 | 1940 | 1941 | 1942 | 1943 | 1944 | 1945 | 1946 | 1947 | 1948 | 1949 | MAPE |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1939 | +166.7% | +283.3% | +400.3% | +517.0% | +633.7% | +750.3% | +867.3% | +984.0% | +1100.7% | +1217.3% | +1334.3% | 5147% |
| 1940 | +125.0% | +189.0% | +226.5% | +264.0% | +301.5% | +339.1% | +376.6% | +414.1% | +451.6% | +489.2% | 2550% | |
| 1941 | +111.1% | +148.6% | +162.7% | +176.9% | +191.0% | +205.2% | +219.3% | +233.5% | +247.6% | 1945% | ||
| 1942 | +10.5% | +52.3% | +38.9% | +25.4% | +11.9% | -1.5% | -15.0% | -28.4% | 629% | |||
| 1943 | -4.8% | -55.4% | -101.2% | -146.9% | -192.6% | -238.3% | -284.1% | 476% | ||||
| 1944 | -12.5% | -71.4% | -110.5% | -149.6% | -188.6% | -227.8% | 400% | |||||
| 1945 | -14.3% | -64.1% | -91.5% | -118.9% | -146.3% | |||||||
| 1946 | -64.1% | -91.5% | -118.9% | -146.3% |
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.