Statistics: Reporting Systems and Methods

Simultaneously with the emergence of the discipline of statistics in the seventeenth century, the fledgling discipline's luminaries began to call for crime statistics in order to "know the measure of vice and sin in the nation" (Sellin and Wolfgang, p. 7). It was not until the nineteenth century that the measurement of a nation's moral health by means of statistics led to the development of the branch of statistics called "moral statistics." France began systematically collecting national judicial statistics on prosecutions and convictions in 1825. For the first time, comprehensive data on crime were available to the overseers of moral health, as well as to researchers. The French data became the source of the first significant statistical studies of crime, by the Belgian Adolphe Quetelet and the Frenchman Andre Michel Guerry, who have been called the founders of the scientific sociological study of crime. Soon afterward, similar analytical and ecological studies of crime were carried out by other Europeans who were influenced directly by, and made frequent references to, the work of Quetelet and Guerry.

In the United States, the earliest crime statistics were state judicial statistics on prosecutions and convictions in court and on prisoners in state institutions. New York began collecting judicial statistics in 1829, and by the turn of the twentieth century twenty-four other states had instituted systems of court data collection. Prison statistics were first gathered in 1834 in Massachusetts, and twenty-three other states had begun the systematic collection of prison data by 1900 (Robinson). The early state data on imprisonment were augmented by the first national enumeration of persons institutionalized in prisons and jails as part of the 1850 census and by subsequent decennial (taken every ten years) population counts thereafter. These early United States Bureau of the Census statistics are relatively complete and informative, including for each prisoner the year and offense of commitment, sex, birthplace, age, race, occupation, and literacy status.

By the end of the nineteenth century, most European countries and a number of states in the United States were systematically collecting judicial and prison statistics, and concomitantly most of the problems relating to these statistics and the measurement of crime in general had been identified. Numerous critics pointed to the fact that judicial and prison statistics were "incomplete" measures of the actual amount and distribution of crime in the community, primarily because of the "dark figure" of undetected, unreported, unacted upon, or unrecorded crime. It has always been clear that not all crimes committed in the community come to the attention of the police, that only a portion of crimes known to the police eventuate in arrest, that not all offenders who have been arrested are prosecuted or convicted, and that only a small fraction of the cases where there is a conviction lead to imprisonment. This underestimation of the volume of crime is not necessarily problematic if, as Quetelet suggested, we "assume that there is a nearly invariable relationship between offenses known and adjudicated and the total unknown sum of offenses committed" (p. 18). In other words, if there is a constant ratio between the actual amount of crime (including the dark figure of unknown offenses) and officially recorded crime, whether recorded by arrest, prosecution, conviction, or imprisonment, then the latter is "representative" of the former and acceptable as a measure of crime. Later research showed this to be a fallacious assumption, but during the nineteenth century and through the first quarter of the twentieth century, scholars and practitioners alike generally operated under this assumption in using and defending judicial statistics as the true measure of crime in a society. Critics pointed to the fact that judicial statistics were not representative of the actual number of crimes or criminals in their proposals that police statistics, particularly of "offenses known to the police," be used in the measurement of crime.

Beginning in 1857, Great Britain was the first nation to systematically collect police data, including offenses known to the police. The significance of this type of data was appreciated by only a few nineteenth-century scholars, among them Georg Mayr, the leading criminal statistician of the time. In 1867, he published the first statistical study using "crimes known to the police" as the primary data source, proposing that crimes known to the police should be the foundation of moral statistical data on crime (Sellin and Wolfgang, p. 14). A few researchers called for utilization of police statistics, but judicial statistics on prosecution and conviction remained the crime statistic of choice in studies of the amount and distribution of crime.

Although the origin, utilization, and defense of judicial statistics were a European enterprise, the emergence of police statistics as a legitimate and eventually favored index of crime can be characterized as an American endeavor. As a result of a growing dissatisfaction with judicial statistics and of the fact—axiomatic in criminology—that "the value of a crime rate for index purposes decreases as the distance from the crime itself in terms of procedure increases" (Sellin, p. 346), the American criminologist August Vollmer in 1920 proposed a national bureau of criminal records that, among other tasks, would compile data on crimes known to the police. In 1927 the International Association of Chiefs of Police made this suggestion an actuality by developing a plan for a national system of police statistics, including offenses known and arrests, collected from local police departments in each state. The Federal Bureau of Investigation became the clearinghouse for these statistics and published in 1931 the first of its now-annual Uniform Crime Reports (UCR). That same year, "offenses known to the police" was accorded even more legitimacy as a valid crime statistic by the Wickersham Commission, which stated that the "best index of the number and nature of offenses committed is police statistics showing offenses known to the police" (U.S. National Commission on Law Observance and Enforcement, p. 25). Ever since that time, "offenses known to the police" has generally been considered the best source of official crime data. However, most of the European countries that had developed national reporting systems of judicial statistics did not include police statistics, particularly crimes known, until the 1950s, and ironically, Great Britain did not acknowledge that crimes known to the police was a valid measure of crime until the mid-1930s, although these data had been collected since the mid-nineteenth century (Sellin and Wolfgang, pp. 18–21).

According to Thorsten Sellin's axiom, "crimes known to the police" has the most value of all official measures of crime because it is closest procedurally to the actual crime committed, probably as close as an official crime statistic will ever be. Even so, as with each and every measure and crime statistic, there are problems regarding even this best of official crime statistics.