Suspicious Discontinuities
5 hours ago
- #data-analysis
- #discontinuities
- #threshold-effects
- Discontinuities in systems such as voting on link aggregators create sharp differences in traffic based on hitting thresholds like front-page status.
- Pell Grants intended to aid low-income students led to adverse outcomes, with higher-income qualifiers benefiting more and lower-income non-qualifiers being disproportionately harmed.
- Spikes in election results at round numbers (e.g., 95%) suggest election fraud, as seen in Russian elections and supported by Benford's law.
- Discontinuities in auction bids, like those in Japanese procurement, indicate potential collusion when bidders maintain ranks across rounds.
- Psychology papers show a spike in p-values just below 0.05, reflecting incentives to achieve statistical significance, prompting calls to abolish such thresholds.
- Cocaine possession charges spiked at 280g after the Fair Sentencing Act, highlighting prosecutorial discretion in meeting mandatory minimum thresholds.
- Polish high school exit exams exhibit a discontinuity at the passing score of 30, with teachers inflating grades in subjective subjects to avoid failures.
- Birth month affects youth sports participation, with older-within-year players having advantages due to age cutoffs, persisting despite known inefficiencies.
- Restaurant health inspection grades show discontinuities at grade boundaries (e.g., between A and B), suggesting inspectors may nudge scores.
- Marathon finishing times cluster at round numbers (e.g., half-hours), as runners adjust pace to hit these targets.
- Discontinuities can be detected via histograms, scatterplots, and CDFs, and smoothed using randomization or queue management techniques.