Suspicious Discontinuities (2020)
5 days ago
- #threshold-effects
- #data-anomalies
- #discontinuities
- Voting in link aggregators causes traffic discontinuities based on front page status, akin to dropping a link from a queue without enough votes.
- Pell Grants as proxies for low-income student support lead to perverse outcomes, benefiting higher-income qualified students and harming lower-income non-qualified ones, with parents potentially gaming income thresholds.
- Russian election data shows spikes at round numbers like 95%, indicating election fraud through fabricated results without smooth distributions.
- U.S. auto auction sales exhibit discontinuities at $10k boundaries in prices and volume, suggesting market anomalies or manipulation.
- Psychology papers show a spike in p-values just below 0.05, indicating questionable research practices like p-hacking, with calls to abolish statistical significance thresholds.
- Cocaine possession charges bunch at 280g after the Fair Sentencing Act, driven by prosecutorial discretion rather than police seizures.
- Polish language exit exam scores spike at 30 due to teacher intervention to prevent failures, highlighting issues with bright-line thresholds in education.
- Youth sports participation correlates strongly with birth month, creating discontinuities where slightly older athletes have advantages, persisting despite known inefficiencies.
- Japanese procurement auctions reveal collusion through bid discontinuities, where second-lowest bidders rarely outbid first-lowest in subsequent rounds.
- Restaurant health inspection grades show discontinuities between letter grades, suggesting inspector discretion influences final scores.
- Marathon finishing times bunch at round numbers like half-hours, as runners adjust pace to meet time goals.