The Nonprime Mortgage Crisis and Positive Feedback Lending
Bibliographic record
Abstract
The “great recession” of 2007–2009 was sparked by a bubble in U.S. housing prices, driven in turn by a bubble in nonprime mortgage lending. We collect evidence that the risk of a nonprime housing bubble (not the certainty, but a meaningful risk) should have been obvious to the main participants in the markets for nonprime lending and related mortgage-backed securities (nonprime MBS), including originators, securitizers, rating agencies, money managers, and institutional investors. Those who did not see the risk were, in many cases, willfully blind. We also discuss the strong positive feedback nature of typical nonprime mortgages. This positive feedback made it highly likely that, if nonprime housing prices flattened, let alone fell, they would soon crash and take many nonprime MBS with them. We discuss regulatory responses that might limit positive feedback lending, cause the next bubble to be smaller and less likely, and make the post-bubble aftermath less painful.
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 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 | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.000 | 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".