I have noticed previous reposts from RBoMI did not get much engagement if at all, so I am going for a single topic per post now.

Men make up a large majority of the prison population: 93% in the United States (2006) [1] and 96% in England & Wales (2013) [2]. Men do commit more crime overall, but numerous studies show that even accounting for legally relevant factors (like crime and criminal history), men receive substantially harsher sentences. Crimes with women as victims also receive harsher sentences.

Examples/evidence: Sonja B. Starr of the University of Michigan controlled for legally relevant factors and found that men receive 63% longer sentences on average. In addition, women were more likely to avoid charges, convictions, and incarceration in the first place [3]. David B. Mustard of the University of Georgia controlled for similar factors and also found that men (and blacks) receive harsher sentences [4].

Last, blacks and males are also less likely to get no prison term when that option is available; less likely to receive downward departures; and more likely to receive upward adjustments and, conditioned on having a downward departure, receive smaller reductions than whites and females.

A group of researchers at the University of Texas at El Paso summarize previous research and explain that women receiving milder sentencing "may be one of the best established facts regarding criminal justice outcomes". It has been found in a wide range of studies since the 1980s, and in numerous different jurisdictions in the United States. They add to the research by looking specifically into different types of crime, finding some differences [5].

For both property and drug offending, females are less likely to be sentenced to prison and also receive shorter sentences if they are sentenced to prison. For violent offending, however, females are no less likely than males to receive prison time, but for those who do, females receive substantially shorter sentences than males.

Cassia Spohn of Arizona State University provides an overview of many other studies showing similar sentencing disparities (in sentence length and likelihood of getting jail time in the first place) [1]. She also cites interesting work on the perception of gender by judges as the reason for these disparities.

The explanation offered by Spohn and Beichner (2000) also focuses on judges’ perceptions and stereotypes of men and women. They suggest that the findings of their study lend credence to assertions that court officials attempt to simplify and routinize the sentencing process by relying on stereotypes that link defendant characteristics such as race or ethnicity and gender to perceptions of blameworthiness, dangerousness, and risk of recidivism. They note that criminal justice officials interviewed for the study admitted that they viewed female offenders, particularly those with dependent children, differently from male offenders.

Another study from the group of researchers at the University of Texas at El Paso looked at the gender of the victim, finding that crimes against women receive harsher sentences than crimes against men [6]. Cassia Spohn cites Williams, Demuth, and Holcomb (2007) who controlled for legally relevant factors and found that offenders convicted of crimes against women were more than two-and-a-half times more likely to be sentenced to death [1]. Another study looked specifically at vehicular homicide and found gender bias [7].

In particular, victim characteristics are important determinants of sentencing among vehicular homicides, where victims are basically random and where the optimal punishment model predicts that victim characteristics should be ignored. Among vehicular homicides, drivers who kill women get 56 percent longer sentences. Drivers who kill blacks get 53 percent shorter sentences.

The harsher treatment of men in the justice system has effects on men long after they do their time. From The New York Times article "Out of Trouble, but Criminal Records Keep Men Out of Work" [8]:

The share of American men with criminal records — particularly black men — grew rapidly in recent decades as the government pursued aggressive law enforcement strategies, especially against drug crimes. In the aftermath of the Great Recession, those men are having particular trouble finding work. Men with criminal records account for about 34 percent of all nonworking men ages 25 to 54, according to a recent New York Times/CBS News/Kaiser Family Foundation poll.

1 ("Sentencing Disparity and Discrimination: A Focus on Gender", chapter 4 of "How Do Judges Decide? The Search for Fairness and Justice in Punishment" by Cassia Spohn)

2 (British House of Commons Library document “Prison Population Statistics”)

3 and alt source (“Estimating Gender Disparities in Federal Criminal Cases” (2012) by Sonja B. Starr)

4 (“Racial, Ethnic, and Gender Disparities in Sentencing: Evidence from the U.S. Federal Courts” (2001) by David B. Mustard)

5 (“Gender Differences in Criminal Sentencing: Do Effects Vary Across Violent, Property, and Drug Offenses?” (2006) by S. Fernando Rodriguez, Theodore R. Curry, & Gang Lee)

6 (“Does Victim Gender Increase Sentence Severity? Further Explorations of Gender Dynamics and Sentencing Outcomes” (2004) by Theodore R. Curry, Gang Lee, & S. Fernando Rodriguez)

7 (“The Determinants of Punishment: Deterrence, Incapacitation and Vengeance” by Edward L. Glaeser and Bruce Sacerdote)

8 (The New York Times article "Out of Trouble, but Criminal Records Keep Men Out of Work")