In addition to the fifth-highest incarceration rate in the country, Arizona also has a 49 percent recidivism rate, which shows that “the threat of a harsher sentence for a subsequent conviction does nothing to make people clean and sober,” the study says.

Although 75 percent of people in Arizona prisons were assessed by the Department of Corrections as having significant substance-abuse histories, only 1.7 percent of prisoners in December 2015 were receiving treatment.

“I think this is definitely a good start for us to understand the sentencing practices related to drug crimes, as well as patterns of arrests and the need for rehabilitation programs while incarcerated,” said Shi Yan, an assistant professor at Arizona State University’s School of Criminology and Criminal Justice.

The study also found evidence of racial disparities in sentencing in the state. African-Americans make up only 4.8 percent of the total general population, but make up 11.5 percent of the population of people who are arrested and 13.8 percent of the prison population.

“The sentence disparity isn’t very surprising, because research in multiple jurisdictions has found that there has been some unexplained disparity between the sentence received by African-Americans and white, and in this case, Hispanic defendants,” Yan said.