
Constructing an RRI MatrixIf you think of the juvenile justice system as a set of individual decisions, the RRI concept can be used to assess the level of racial disparity introduced at each decision point  if the numerator and denominator used to construct the rates are carefully selected. For example, what should be the numerator and denominator to assess disparity at the point of referral to juvenile court? The numerator is rather obvious, some measure of referrals to juvenile court (e.g., number of referrals disposed in 2010 or the number of offenses referred in 2010). One possibility for the denominator is juvenile population, the same as we used at the arrest decision; but this choice has inherent problems  and understanding this point is key to developing and appropriately interpreting the RRI. Using population as the denominator for the juvenile court referral rate yields a rate whose magnitude could depend on many factors (e.g., the level of delinquency behavior, the level of reporting crime to law enforcement, and any disparities or biases in the arrest process). But we already have a measure of disparity at the arrest decision; so by using population as the denominator in the court referral decision rate, the rate will really be a combination of the disparity at the arrest decision plus any additional disparity added at the court referral decision. To isolate the disparity introduced at the court referral decision, a better denominator for the court referral would be the number of arrests. Using this, the court referral rate for each racial group would answer the question "For every 100 arrests of white youth in our jurisdiction, how many court referrals occurred in 2010?" Using this denominator, any disparity in the arrest decision is removed from the calculation, and any resulting disparities between the white and the minority juvenile court referral rate can be attributed to the referral process and not disparities in the amount of crime juveniles commit or the disparities with the arrest process. Therefore, the general rule in creating the rates to be used in an RRI is to select a denominator that captures the decisionmaking stage immediately preceding the stage measured by the numerator or, in other words, the stage that feeds the numerator. For example, to a great extent arrests feed juvenile court referral; if arrests increase, most likely juvenile court referrals will increase. There are certainly other paths to juvenile court beyond arrest (e.g., parents may refer the youth or a probation officer may refer a youth back to court on a probation violation); but arrest is the most controlling preceding stage. Using this logic, a measure of:
For each racial group, using a set of decision process rates (e.g., arrest rate, juvenile court referral rate, detention rate, diversion rate, petition rate, waiver rate, adjudication rate, etc.) an RRI can be developed. By dividing one group's rate for a decision point by another group's rate at the same decision point, the relative rate (or the relative size of one rate to the other) can be calculated. Some decisions increase the extent of minority youth contact with the justice system. Other decisions (those with Relative Rate Indices equal to 1.0) neither increase nor decrease disparity but maintain the level of disparity that resulted from prior decisions. The magnitude of racial disparity at any decision point in the juvenile justice system is a combination of the disparities introduced at prior decision points plus that added by the decision point of interest. Studying the set of Relative Rate Indices for a specific decision process enables us to see the unique contributions made by each decision point to the overall disparity in the system. Developed and maintained by the National Center for Juvenile Justice, with funding from the Office of Juvenile Justice and Delinquency Prevention (OJJDP), Office of Justice Programs, U.S. Department of Justice.
