IDENTIFYING MISSING DATA
In this data collection, zeroes may represent both true zeroes and missing data, and it is possible to distinguish between the two.
For crimes reported, data cannot be estimated for non-reporting agencies. Therefore, counties with no population for reporting agencies will also have a coverage indicator of zero and all crime variables will have a value of zero. These zeroes indicate missing data. If a county has one or more offense variables with a value of zero, but has a value of greater than zero for the population and coverage indicator variables, then the zeroes for these particular offense variables should be considered true zeroes for the purposes of analysis.
SUMMARY OF HOW TO IDENTIFY MISSING DATA FOR CRIMES REPORTED
TRUE ZERO: Coverage indicator > 0
MISSING DATA: Coverage indicator = 0
(All other crime count variables will be necessarily = 0)
In the UCR county-level crimes reported files, the population and crime data for jurisdictions located in multiple counties are provided by the UCR proportioned to each county (maximum of three) in which the jurisdiction is located. Drunkenness (FBI offense code 23) is not considered a crime in some states. States that do not consider drunkenness a crime, but which report data through the NIBRS system, such as North Dakota, may show arrest data for the offense in this data collection. This is because drunkenness may be listed as an incident in the National Incident Based Reporting System (NIBRS) reporting system, even though there was technically no arrest in these states. Agencies in states where drunkenness is not a crime may use their own discretion in reporting drunkenness as an incident. Users should exercise caution when analyzing this variable because of these differences in reporting.
For arrest information, the population and data for jurisdictions located in multiple counties are provided only in the county containing the largest population component of the jurisdiction. Counties containing smaller population components of multiple-county jurisdictions will contain no population or arrest data for these jurisdictions.
Finally, the original data from the FBI contain one record for New York City. Data from New York City are allocated into New York City's five counties on the basis of the proportion of the population in each county. For example, the population for Queens county is divided by the total population of New York City and the resulting proportion is multiplied with data from each of New York City's arrest and offense categories to apportion data to Queens county. Population numbers from the 2000 Census were used to calculate these proportions.
Three hundred and thirteen dummy records were created for the crimes reported data files for counties not represented in the original FBI file. These county records provide only the state and county FIPS codes with the rest of the variables following county FIPS in the data file filled with zeros. Limited crimes reported data were available for Illinois, Kentucky, Mississippi, Missouri, Montana, and South Dakota.
INFORMATION PERTAINING TO THE USE OF GEOGRAPHIC IDENTIFIERS
Cities designated by the Census Bureau as independent cities are reported separately and have their own "county" codes. Some jurisdictions, such as state parks and some state police, provide data only on a statewide basis. In these cases, data are allocated to counties proportionate to their share of the total state population. State Police data for Vermont that were not reported within a county and the State Police data for Alaska are not allocated to the counties. These two State Police records are identified by the county code 999. In the 1997 data and onward another 999 county code was added to these data files. The New York/New Jersey Port Authority reported data in 1997 through two agencies, one in New York and one in New Jersey. The FBI included the New York Port Authority agency as part of New York county. However, the FBI did not assign a UCR county code for the New Jersey Port Authority and did not provide a population figure for the area covered by this jurisdiction. Therefore, the New Jersey/New York Port Authority (NJNYPOA) is a separate record in the data files from 1997 onward with a county code of 999. This change increases the number of counties in this data collection to 3,145.
NACJD uses Federal Information Processing Standard (FIPS) Publication 6-4 "Counties and Equivalent Entities of the United States, Its Possessions, and Associated Areas" from the National Institute of Standards and Technology (NIST), U.S. Department of Commerce, as a reference for assigning FIPS codes for the counties in this data collection. NACJD consults this publication annually to note changes in FIPS codes that may affect this collection. In May 1995, the National Institute of Standards and Technology (NIST) announced that the independent city of South Boston, Virginia reverted to town status and became part of Halifax County as of June 30, 1995. The Virginia FIPS county code of 780 no longer exists and South Boston is included in FIPS county code 083. Information was not adjusted this data collection to reflect this change so that the data files would remain consistent with earlier years. Users who wish to use the current FIPS codes can combine the data from South Boston with Halifax County.
In July 1999, NIST announced that Yellowstone National Park, which had been treated as a county equivalent, is legally part of Gallatin County and Park County, Montana. Yellowstone National Park was left as a county equivalent in this data collection to remain consistent with earlier years.
In July 1999, NIST announced that as of November 13, 1993 Dade County, Florida officially changed its name to Miami-Dade County. The county was assigned a new FIPS code (086) to maintain the alphanumeric sequence of counties. In the 1997 data collection and onward, this change to the Miami-Dade county code from 025 to 086 was made to match the change in the FIPS publication. However, the 1993- 1996 UCR county-level data collections still used the old name and FIPS county code.
Note: The above discussion draws heavily from the information presented in the codebook "UNIFORM CRIME REPORTING PROGRAM DATA [UNITED STATES]: COUNTY-LEVEL DETAILED ARREST AND OFFENSE DATA, 2000 (ICPSR 3451)", published by the University of Michigan's Inter-University Consortium's (ICPSR) National Archive of Criminal Justice Data (NACJD) group, from which the data displayed here were drawn from.
Page Last Modified: April 20, 2007