Self-report statistics are stats that are reported by individuals. Self-report statistics get gathered when people are asked to report the number of times they may have committed a particular crime during a set period in the past, regardless of getting caught or not. For example, in-class students take a criminal activity checklist and report behaviors they have engaged in at some point in their lives. People should be honest since the data has no identifying information collected, and report even if no one ever found out what we find during class time it that all the students, for over eight years of teaching, have committed a crime. However, the amount of students that have to get caught is minimal, especially those that received formal sanctioning from the CJ system (funneling of crime).
Survey Research Center in the Institute for Social Research at theUniversity of Michigan.
In the Report: One Form of Drug Use Showed a Sharp Increase in Use in 2018
The most important findings to emerge from the 2018 survey is the dramatic increase in vaping by adolescents. Vaping is a relatively new phenomenon, so we are still developing measures related to this behavior, which included asking separately for the first time in 2017 about the vaping of three specific substances—nicotine, marijuana, and just flavoring. As the section on vaping in this monograph shows, there was a significant and substantial increase in 2018 in the vaping of all three of these substances, including some of the most substantial absolute increases MTF has ever tracked for any substance. Given that nicotine is involved in most vaping, and given that nicotine is a highly addictive substance, this presents a severe threat.
Self-report statistics are great because they can help discover problems we were unaware of, such as vaping. Further, it helps us identify victimless crimes, or crimes to where there is no victim such as drug use, gambling, and underage drinking. Lastly, we uncover offenses that are not as serious such as shoplifting, which is less likely to be known to police. 
However, self-report data also has its limitations. Respondents may exaggerate or underreport their criminal behavior, for various reasons. For example, in the class activity, we do many students did not know what they did was illegal behavior until the statute was read, so they would never have thought they committed a crime. Lastly, if we do not capture a large sample, we may limit who gets the survey. If we are surveying kids in school about substance abuse, but not reaching out to all kids even if they get suspended, we may miss important data. 
In each type of data (official, self-report, and victimization) there are pros and cons. Additionally, each source is more likely to produce a better picture of what is occurring depending on the area of study. If a person wanted to get the best statistics on reported homicides in the US, which source would be best? How about domestic violence? What if we were interested in finding out drug abuse rates amongst teens in high school?
- Johnston, L.D., Miech, R.A., O’Malley, P.M., Bachman, J.D., Schulenberg, J.E., & Patrick, M.E. (2018). MTF. 2018 Overview Key Findings on Adolescent Drug Use ↵
- ohnston, L.D., Miech, R.A., O’Malley, P.M., Bachman, J.D., Schulenberg, J.E., & Patrick, M.E. (2018). MTF. 2018 Overview Key Findings on Adolescent Drug Use ↵
- Hindelang, Hirschi, & Weis, (1981). Measuring delinquency. Thousand Oaks, CA: Sage Pubs. ↵
- Lab, S., Holcomb, J., & King, W. (2013). Criminal justice: The Essentials. Oxford University Press: Oxford. ↵