Average Number of Personal Robberies Reported Per Day by Month (US 1999)
Brian A. Reeves, BJS
the SPSS syntax file
This table looks at the time of day robberies occur at various types of
locations. To create this table, time is grouped into 4-hour categories.
Robbery offenses are then selected. Location is also grouped, and a cross-tabulation
table is created. 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, the COMPUTE creates the
variable pers_rob and sets the value to 0. The IF transformation selects all
incidents with at least one robbery and where at least one individual (person) was a
victim. SELECT IF chooses all cases in which the pers_rob variable had a value equal
to 1. The file is saved to a new file. VALUE LABELS assigns the name of the
month to the corresponding numerical value in the variable inc_mo.
GET FILE='Directory\Path\incident 1999.sav'.
COMPUTE pers_rob = 0.
IF (rob ge 1 and indivl ge 1)pers_rob = 1.
SELECT IF (pers_rob = 1).
SAVE OUTFILE='Directory\Path\Personal Robberies 1999.sav'.
VALUE LABELS inc_mo 1 'January' 2 'February' 3 'March' 4 'April'
5 'May' 6 'June'
7 'July' 8 'August' 9 'September' 10 'October' 11
'November' 12 'December'.
|Cases are first sorted in ascending order (A) by inc_mo and inc_dy. The
AGGREGATE restructures the data and changes the unit of analysis to incident month.
The data are saved in a new file.
SORT CASES BY
inc_mo (A) inc_dy.
/OUTFILE = 'Directory\Path\inc_mo agg.sav'
/inc_dy = LAST(inc_dy)
GET FILE = 'Directory\Path\inc_mo agg.sav'.
|COMPUTE creates the new variable avg_dy that is equal to the number of robberies (rob)
divided by the incident day (inc_dy). The FORMATS command indicates the number of
places beyond the decimal that will be displayed.
FORMATS avg_dy (f8.0).
|Producing the Output. To produce the data necessary to replicate the
table, two tables must be created. For the first table, the output is
defined as a table that displays the average number of personal robberies reported per day
/FORMAT BLANK MISSING ('.')
/TABLE=inc_mo BY avg_dy
/STATISTICS mean(avg_dy 'Daily Average')
/TITLE 'Average Number of Personal Robberies' 'Reported per Day by Month (US
|For the second table, only robberies with an actual date and time are selected for
analysis; incidents coded with a "report" date are excluded. This example
also assumes that inc_hr is reported correctly; incidents coded as occurring at midnight
FILE='Directory\Path\Personal Robberies 1999.sav'.
DO IF (rptdate = ' ').
RECODE inc_hr (0 thru 3 = 1)(4 thru 7 = 2)(8 thru 11 = 3)(12 thru 15 = 4)(16 thru 19 = 5)
(20 thru 23 = 6)INTO time.
VALUE LABELS time 1 'Mid - 3:59 am' 2 '4 - 7:59 am' 3 '8 - 11:59 am' 4
'Noon - 3:59 pm'
5 '4 - 7:59 pm' 6 '8 - 11:59 pm'.
|When using the 1999 NIBRS data, the resulting tables look like this: