There is a case study of literacy and prison libraries, including information on demographics with a discussion of "empowerment" published in 1993; here is the citation:
Shethar, A. (1993). Literacy and "Empowerment"? A Case Study of Literacy behind Bars. Anthropology & Education Quarterly 24(4):357-372.
From the abstract:
"A Chicano prison inmate's progress in a year-long literacy tutorial course demonstrates ways in which writing can negotiate and reorganize race, class, gender, and power identities for both tutor and student, and legitimize the student's voice, native language, and discourse stance. Through dialogue, the student progresses from the passive-learner role to a presentation of self as knowledgeable expert; from denial of his prison group-membership, he progresses to a critical analysis of the power structure it represents."
Literacy Behind Bars: Results From the 2003 National Assessment of Adult Literacy Prison Survey, from the IES National Center for Education Statistics might also help you:
"The findings in this report—Literacy Behind Bars—indicate the changes in literacy among incarcerated adults between 1992 and 2003. The report also compares the literacy of adults in the prison and household populations and across groups of prison inmates with different characteristics, including race/ethnicity, gender, educational attainment, age, language spoken before starting school, and parents’ educational attainment. The report looks at the relationship between literacy, education, and job training, including traditional academic education, vocational education, and skill certification. Additionally, the report examines the relationship between literacy and experiences in prison other than education, including prison work assignments, library use, computer use, and reading frequency. Finally, the report looks at the relationship between literacy, criminal history, and current offense. The results show how the relationship between literacy, type of offense, expected length of incarceration, expected date of release, and previous criminal history has changed since 1992."
