Relationship, enables
Capital investment enables Economic output
The stored status is what a reviewer approved. The level below it is what the overlapping data support; the two are shown side by side and only a human moves the status.
Mechanism, evidence, reviewer judgements
The edge as stored
Capital investment enables Economic output2 evidenceHypothesized
Economic output depends on Capital investment.
Mechanism
Stated, not yet evidenced here: the share of output reinvested in buildings, machines and infrastructure raises the capital stock and, with a lag, output per person (the accumulation term in growth accounting). Investment also responds to expected growth, so the direction runs both ways.
Evidence
- metricgross-capital-formation-share
- metricgdp-per-person
- Status
- hypothesized
- Reviewer confidence
- 0.60
- Stated strength
- not stated
- Lag
- not stated
- Version
- curated_seed_v1
- Reviewed
- 2026-09-07
Confidence and strength are curated judgements recorded with the edge, not measured quantities.
Entity pages: Capital investment, Economic output.
Level 1 evidence, computed 2026-09-07 22:15 UTC
Correlation
Gross capital formation as share of GDP against GDP per person, constant 2015 US$, geography WLD, 55 overlapping years (1970 to 2024). Primary statistics on diff (first differences, because at least one series has a unit root; levels are shown for comparison).
Pearson r (diff)
0.626
p 0.0000
Spearman rho (diff)
0.716
p 0.0000
Pearson r (levels)
0.005
two trending series correlate in levels by construction
Rolling r
0.853
min 0.394, max 0.966, 0 sign changes
- significant association on diff (n 55)
- no one-way predictive lead/lag
Cross-correlation scan and Granger-style tests
Lead and lag
| Direction | Tested | lag 1 p | lag 2 p | lag 3 p | lag 4 p | lag 5 p | min p | Reading |
|---|---|---|---|---|---|---|---|---|
| Gross capital formation as share of GDP helps predict GDP per person, constant 2015 US$ | yes | 0.494 | 0.596 | 0.758 | 0.834 | 0.802 | 0.4943 | no predictive information beyond own past |
| GDP per person, constant 2015 US$ helps predict Gross capital formation as share of GDP | yes | 0.996 | 0.690 | 0.739 | 0.722 | 0.593 | 0.5934 | no predictive information beyond own past |
Granger-style F-tests on the primary transform: whether lagged values of one series improve a regression of the other on its own lags. Predictive information is not causation; a common driver that moves one series earlier produces the same pattern.
Reading: neither series adds predictive information about the other beyond its own past.
- Cointegration
- no (p 0.233)
- Changepoints
- Gross capital form: 2, GDP per person, co: 1
- ADF p (levels)
- 0.096, 0.997
- Service
- causal-service/0.1.0
Not computed
Causal estimate
Alternative explanations for the association
What else could explain it
- Both series trend with world development; the primary statistics use first differences to limit that, not remove it.
- A common driver (income, urbanisation, technology) can move both series with different lags and produce a lead/lag pattern without any direct effect.
- World aggregates hide country composition: a change in which countries report can move a world series.
- Reverse direction: Economic output may act on Capital investment.
- Both series are revised by their source; the analysis uses the current vintage, not the vintage available at the time.
What each rung means
Levels
- Level 0: No association found
the overlapping data show no significant association.
- Level 1: Correlation only
statistically associated in the overlapping periods; no direction, no mechanism.
- Level 2: Predictive lead/lag
one series historically contains predictive information about the other.
- Level 3: Mechanism supported
a documented physical, economic or institutional mechanism with cited evidence.
- Level 4: Causally supported
a backdoor-adjusted estimate that survived refutation, on stated assumptions.
- Level 5: Established relation
follows from engineering, accounting or scientific structure.
Every stored run, newest first
Analysis history
- 2026-09-07 22:15 correlate level 1 n 55 causal-service/0.1.0