Market Efficiency in the MENA Equity Markets: Evidence from Newly Developed Tests and Regime Change
Bibliographic record
Abstract
A major issue in financial economics is the behavior of stock market returns over long horizons. This paper provides an empirical investigation of the random walk hypothesis in the MENA equity markets. We use the variance ratio tests developed by Wright (2000), Kim and Wang and Chow Denning (1993) to test for the weak form market efficiency. Then, we use the unit root tests proposed by Saikkonen and LA¼tkepohl (2002) and Lanne et al . (2002), which allow for a level shift in the data generating process. Our results confirm the stationarity of the MENA equity markets returns in the presence of structural breaks, with the breaks happening mostly during the 2008 and 2009 periods. Further, the findings from our sub-samples indicate that the results from the last sub-periods support the belief that these markets may have been approaching a state of being fairly weak-form efficient, which reflects the future prospects of the MENA countries.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.008 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
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 teacher head, 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".