Seasonality in US Prisoner Statistics from Early 20th Century

Seasonality in jail populations is different from that for federal and state penal populations.

US Jail Inmate Population Data

The U.S. Bureau of Justice Statistics’ Annual Survey of Jails provides data on jail populations annually from 1982, with some missing years.

Readily accessible, structured data from the United Nations Crime Trends Surveys: 2nd (1975-1980), 9th (2003-2004), and 10th (2005-2006).

The prisoner sex-ratio dispersion index is the natural log of the ratio of the 3rd to the 1st quartile in the distribution of prisoner sex ratios.

The aggregate sex ratio is the sex ratio in the total population, ignoring jurisdictional distinction. The average sex ratio is less meaningful.

The distribution of prisoner sex ratios across 209 jurisdictions worldwide about the year 2010 is approximately log normal.

Prisoner sex-ratio dispersion has not always decreased when in the median prisoner sex ratio has decreased.

Statistics on prisoners world-wide are among the best quality international statistics available. They deserve more scholarly and policy attention.

Compared to sex shares, sex ratios are more likely foster popular understanding and insight.

Converting a sex share to the corresponding sex ratio involves only easy algebra.