### Burns, BD (2020)

#### Do people fit to Benford’s law, or do they have a Benford bias?

Proceedings of the 42nd Annual Virtual Meeting of the Cognitive Science Society, pp. 1729-1735.

**ISSN/ISBN:** Not available at this time.
**DOI:** Not available at this time.

**Abstract:** Smith (2015) describes an explosion of interest in Benford’s law, that for data from many domains the first digits have a log distribution. Few studies have similarly asked whether the numbers people generate fit to Benford’s law, but recent data show a reasonable fit. This paper argues that testing for fit to Benford’s law is the wrong question for behavioural data, instead we should think in terms of a “Benford bias” in which the first-digit distribution is distorted towards Benford’s law. We propose calculating the effect size of this bias by testing a linear contrast weighted by Benford’s law. Analyses of existing data sets yielded effect sizes of 0.43-0.52. Applying this approach to a new task extended the scope of Benford bias to predicting outputs of a linear system and found an effect size of .40. Benford bias may be a ubiquitous influence on judgments and decisions based on numbers.

**Bibtex:**

```
@inproceedings{,
AUTHOR={Bruce D. Burns},
TITLE={Do people fit to Benford’s law, or do they have a Benford bias?},
BOOKTITLE={Proceedings of the 42nd Annual Virtual Meeting of the Cognitive Science Society},
PAGES = {1729-1735},
YEAR={2020},
URL={https://cognitivesciencesociety.org/cogsci20/papers/0379/0379.pdf},
}
```

**Reference Type:** Conference Paper

**Subject Area(s):** Psychology