TIME OF JUVENILE FIREARM VIOLENCE
South Carolina Department of Public Safety and the University of South Carolina
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This table looks at the occurrence of juvenile firearm violence, comparing
time-of-day categories in weekends and weekdays during the school year. When using
this code, be sure to insert the path and the file name of the data file to be used, as
well as the directory and file name for saving. If you need any assistance working
with the syntax provided, please contact us.
|Preparing the File. The
unit of analysis for this research question is incident. The incident-level flat
file can be used rather than multiple segments (administrative, victim, offense) because
the variables needed were created with the aggregate command in the Creating An
Incident-Level Aggregated Flat File procedure. First, a variable called VIOL_OFF is
created from the most serious incident offense. The IF transformation then selects
all cases where the most serious incident offense is less than or equal to a value of 130
(murder, rape, robbery, aggravated assault). The number 1 represents the presence of
a Part 1 violent index offense and the number 0 represents the absence of a Part 1 violent
GET FILE='Directory\Path\incident 1999.sav'.
COMPUTE viol_off = 0.
IF (msioff le 130) viol_off = 1.
|The TEMPORARY command, followed by the SELECT IF command, chooses records based on
whether the offender's age, violent offense, and firearm variables are all greater than or
equal to one.
SELECT IF (off1017 ge 1 AND viol_off = 1 AND firearm ge 1).
SAVE OUTFILE='Directory\Path\Juv viol firearm incidents.sav'.
|The USEALL defines a USE range starting with the first observation and ending with the
last observation in the series. This COMPUTE illustrates the use of a filter to
limit the analysis to only those incidents that occurred during the school year.
FILE='Directory\Path\Juv viol firearm incidents.sav'.
COMPUTE filter_$=(((inc_mo >=1 & inc_mo <=6) or (inc_mo >=9 & inc_mo
and rptdate = ' ').
VARIABLE LABEL filter_$ 0 'Not Selected' 1 'Selected'.
FORMAT filter_$ (f1.0).
FILTER BY filter_$.
|The first COMPUTE creates a weekday variable. The DATE.DMY puts the variables
INC_DY, INC_MO, and INC_YR into a date format (the data are initially set up with an
incident's day, month and year as separate variables). XDATE.WKDAY then extracts the
weekday of the incident from the date format with the values 1 through 7 representing the
days of the week. VALUE LABELS are assigned to the variable wkday.
COMPUTE created a WEEKEND variable that is set to a value of 1. IF the WKDAY
variable is greater than 2 and less than 6, the variable WEEKEND is equal to 2.
VALUE LABELS are also assigned.
VALUE LABELS wkday 1 'Sunday' 2 'Monday' 3 'Tuesday' 4 'Wednesday'
6 'Friday' 7 'Saturday'.
weekend = 1.
IF (wkday ge 2 and wkday le 6)weekend = 2.
VALUE LABELS weekend 1 'Weekend' 2 'Weekday'.
|Only the incidents with an actual date and time are selected for analysis; incidents
coded with a "report" date are excluded. This example also assumes that
the INC_HR is reported correctly; incidents at zero hours, representing the midnight hour,
are included despite possible data quality issues (see the Data Quality section for a
discussion of this issue).
DO IF (rptdate
= ' ').
RECODE inc_hr (0 thru 6 = 1)(7 = 2)(8 thru 11 =3)(12 thru 14 = 4)(15 thru 17 = 5)
(18 thru 20 = 6)(21 thru 23 = 7)INTO time.
VALUE LABELS time 1 'Mid - 6:59 am' 2 '7 -7:59 am' 3 '8 - 11:59 am' 4 'Noon -
5 '3 - 5:59 pm' 6 '6 - 8:59 pm' 7 '9 - 11:59 pm'.
|Producing the Output. The output is defined as a table that
displays the time of day groups by the days of the week. The totals are shown for
both columns and rows. Percentages are calculated for both day of week and time
/FORMAT BLANK MISSING('.')
/FTOTAL=$t000002 BY weekend + $t000001
CPCT (weekend(pct5.1) 'Col %':weekend)
/TITLE 'Time of Juvenile Firearm Violence During the School Year' '(Calendar Year
|Using 1999 NIBRS data, the resulting table looks like this: