Does cointegration of prices of North American softwood lumber species imply nearly perfectly substitutable products?
Bibliographic record
Abstract
This study uses the Engle–Granger cointegration method to examine the correlation relationship among prices of North American softwood lumber species, wood-based panel prices, and US single-family housing starts. The methodology employed is identical to that used by US petitioners in the latest round of the Canada – United States softwood lumber trade dispute, whereby petitioners argued that all North American species of softwood lumber were considered to be nearly perfect substitutes for one another. Tests for nonstationarity using the augmented Dickey–Fuller unit root test, as well as our cointegration results, confirm petitioners’ results. We find evidence of a long-term cointegrating relationship among the prices of North American softwood lumber species. However, we found no clear evidence of nearly perfect substitutability among different North American softwood lumber species. Additional analysis reveals that a long-run equilibrium relationship also exists between North American softwood lumber species and four types of wood-based panel products, as well as US single-family housing starts. Given that the price movements of different wood-based panel products and single-family housing starts are highly correlated with the price movement of North American softwood lumber species, we fail to conclude that North American softwood lumber species can be claimed as nearly perfect substitutes. Furthermore, we find that the petitioners’ analysis is deficient in that it does not account for the fact that cointegration in prices among North American species of softwood lumber can be caused by common demand-side factors, such as residential construction activity.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.002 | 0.011 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.002 |
| Science and technology studies | 0.001 | 0.002 |
| Scholarly communication | 0.002 | 0.003 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.007 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".