I selected the Minneapolis Police Department 2017 Stop Data dataset from [http://vincentarelbundock.github.io/Rdatasets/]

Field Name Details
idNum Character vector or incident identifiers
date A POSITXlt date variable giving the date and time of the stop
problem A factor with levels suspicious for suspicious vehicle or person stops and traffic for traffic stops
MDC A factor with levels mdc for data collected via in-vehicle computer, and other for data submitted by officers not in a vehicle, either on foot, bicycle or horseback. Several of the variables above were recorded only invehicle
citationIssued A factor with levels no yes indicating if a citation was issued
personSearch A factor with levels no yes indicating if the stopped person was searched
vehicleSearch A factor with levels no or yes indicating if a vehicle was searched
preRace A factor with levels white, black, east african, latino, native american, asian, other, unknown for the officer’s assessment of race of the person stopped before speaking with the person stopped
race A factor with levels white, black, east african, latino, native american, asian, other, unknown, officer’s determination of race after the incident
gender A factor with levels female, male, unknown, gender of person stopped
lat Latitude of the location of the incident, somewhat rounded
long Latitude of the location of the incident, somewhat rounded
policePrecint Minneapolis Police Precinct number
neighborhood A factor with 84 levels giving the name of the Minneapolis neighborhood of the incident

I am interested in seeing if there is any correlation between certain holidays and the amount of stops made by the Minneapolis Police Department in 2017. I am going to look at the below holidays:

Holiday Date
New Year’s Day Sunday, January 1, 2017
Mother’s Day Sunday, May 14, 2017
Memorial Day Monday, May 29, 2017
Father’s Day Sunday, June 18, 2017
Independence Day Tuesday, July 4, 2017
Thanksgiving Day Thursday, November 23, 2017
Christmas Day Monday, December 25, 2017

Below is a brief excerpt of the dataset.

##      X     idNum                date    problem MDC citationIssued
## 1 6823 17-000003 2017-01-01 00:00:42 suspicious MDC           <NA>
## 2 6824 17-000007 2017-01-01 00:03:07 suspicious MDC           <NA>
## 3 6825 17-000073 2017-01-01 00:23:15    traffic MDC           <NA>
## 4 6826 17-000092 2017-01-01 00:33:48 suspicious MDC           <NA>
## 5 6827 17-000098 2017-01-01 00:37:58    traffic MDC           <NA>
## 6 6828 17-000111 2017-01-01 00:46:48    traffic MDC           <NA>
##   personSearch vehicleSearch preRace         race  gender      lat
## 1           NO            NO Unknown      Unknown Unknown 44.96662
## 2           NO            NO Unknown      Unknown    Male 44.98045
## 3           NO            NO Unknown        White  Female 44.94835
## 4           NO            NO Unknown East African    Male 44.94836
## 5           NO            NO Unknown        White  Female 44.97908
## 6           NO            NO Unknown East African    Male 44.98054
##        long policePrecinct    neighborhood
## 1 -93.24646              1 Cedar Riverside
## 2 -93.27134              1   Downtown West
## 3 -93.27538              5        Whittier
## 4 -93.28135              5        Whittier
## 5 -93.26208              1   Downtown West
## 6 -93.26363              1   Downtown West
##        X               idNum                        date      
##  Min.   : 6823   17-000003:    1   2017-01-10 12:05:28:    2  
##  1st Qu.:20379   17-000007:    1   2017-01-22 17:33:37:    2  
##  Median :33864   17-000073:    1   2017-01-27 22:40:21:    2  
##  Mean   :33861   17-000092:    1   2017-01-27 23:21:45:    2  
##  3rd Qu.:47387   17-000098:    1   2017-01-30 14:26:45:    2  
##  Max.   :60838   17-000111:    1   2017-02-03 13:35:57:    2  
##                  (Other)  :51914   (Other)            :51908  
##        problem         MDC        citationIssued personSearch
##  suspicious:25822   MDC  :43699   NO  :15899     NO  :38462  
##  traffic   :26098   other: 8221   YES : 3211     YES : 5237  
##                                   NA's:32810     NA's: 8221  
##                                                              
##                                                              
##                                                              
##                                                              
##  vehicleSearch            preRace                race      
##  NO  :40579    Unknown        :28337   Black       :15220  
##  YES : 3120    Black          : 6805   White       :11703  
##  NA's: 8221    White          : 6004   Unknown     : 9219  
##                Native American:  908   East African: 2188  
##                Latino         :  528   Latino      : 1858  
##                (Other)        : 1117   (Other)     : 3511  
##                NA's           : 8221   NA's        : 8221  
##      gender           lat             long        policePrecinct 
##  Female :10015   Min.   :44.89   Min.   :-93.33   Min.   :1.000  
##  Male   :27131   1st Qu.:44.95   1st Qu.:-93.29   1st Qu.:2.000  
##  Unknown: 6492   Median :44.98   Median :-93.28   Median :3.000  
##  NA's   : 8282   Mean   :44.97   Mean   :-93.27   Mean   :3.257  
##                  3rd Qu.:45.00   3rd Qu.:-93.25   3rd Qu.:4.000  
##                  Max.   :45.05   Max.   :-93.20   Max.   :5.000  
##                                                                  
##         neighborhood  
##  Downtown West: 4409  
##  Whittier     : 3328  
##  Near - North : 2256  
##  Lyndale      : 2154  
##  Jordan       : 2075  
##  Hawthorne    : 2031  
##  (Other)      :35667

I am going to focus on the stop dates, so we can remove the other fields for this purpose.

##      stopID   stopDate
## 1 17-000003 2017-01-01
## 2 17-000007 2017-01-01
## 3 17-000073 2017-01-01
## 4 17-000092 2017-01-01
## 5 17-000098 2017-01-01
## 6 17-000111 2017-01-01
##        stopID         stopDate         
##  17-000003:    1   Min.   :2017-01-01  
##  17-000007:    1   1st Qu.:2017-03-29  
##  17-000073:    1   Median :2017-06-17  
##  17-000092:    1   Mean   :2017-06-23  
##  17-000098:    1   3rd Qu.:2017-09-18  
##  17-000111:    1   Max.   :2017-12-31  
##  (Other)  :51914

First let’s look at the information for the entire dataset, that way we can analyze if there is any difference for the holidays. The summary above shows the min, 1st quartile, median, 3rd quartile and max values distributed relatively evenly, being all 3 months apart from each other. This indicates that there is an even distribution of stops throughout the year. The scatterplot and histogram below confirm this.

## [1] "The total number of stops in 2017 is 51920. This averages to 142.2 per day in 2017."

The total number of stops in 2017 is 51,920. This averages to about 142 stops per day. Let’s see if the holidays have similar data.

New Year’s Day

##      stopID   stopDate
## 1 17-000003 2017-01-01
## 2 17-000007 2017-01-01
## 3 17-000073 2017-01-01
## 4 17-000092 2017-01-01
## 5 17-000098 2017-01-01
## 6 17-000111 2017-01-01
##        stopID      stopDate         
##  17-000003: 1   Min.   :2017-01-01  
##  17-000007: 1   1st Qu.:2017-01-01  
##  17-000073: 1   Median :2017-01-01  
##  17-000092: 1   Mean   :2017-01-01  
##  17-000098: 1   3rd Qu.:2017-01-01  
##  17-000111: 1   Max.   :2017-01-01  
##  (Other)  :82

Mother’s Day

##          stopID   stopDate
## 20890 17-174955 2017-05-14
## 20891 17-174989 2017-05-14
## 20892 17-174995 2017-05-14
## 20893 17-174997 2017-05-14
## 20894 17-175005 2017-05-14
## 20895 17-175011 2017-05-14
##        stopID       stopDate         
##  17-174955:  1   Min.   :2017-05-14  
##  17-174989:  1   1st Qu.:2017-05-14  
##  17-174995:  1   Median :2017-05-14  
##  17-174997:  1   Mean   :2017-05-14  
##  17-175005:  1   3rd Qu.:2017-05-14  
##  17-175011:  1   Max.   :2017-05-14  
##  (Other)  :107

Memorial Day

##          stopID   stopDate
## 23132 17-195852 2017-05-29
## 23133 17-195855 2017-05-29
## 23134 17-195863 2017-05-29
## 23135 17-195862 2017-05-29
## 23136 17-195873 2017-05-29
## 23137 17-195874 2017-05-29
##        stopID       stopDate         
##  17-195852:  1   Min.   :2017-05-29  
##  17-195855:  1   1st Qu.:2017-05-29  
##  17-195862:  1   Median :2017-05-29  
##  17-195863:  1   Mean   :2017-05-29  
##  17-195873:  1   3rd Qu.:2017-05-29  
##  17-195874:  1   Max.   :2017-05-29  
##  (Other)  :107

Father’s Day

##          stopID   stopDate
## 26004 17-225104 2017-06-18
## 26005 17-225108 2017-06-18
## 26006 17-225115 2017-06-18
## 26007 17-225127 2017-06-18
## 26008 17-225135 2017-06-18
## 26009 17-225153 2017-06-18
##        stopID      stopDate         
##  17-225104: 1   Min.   :2017-06-18  
##  17-225108: 1   1st Qu.:2017-06-18  
##  17-225115: 1   Median :2017-06-18  
##  17-225127: 1   Mean   :2017-06-18  
##  17-225135: 1   3rd Qu.:2017-06-18  
##  17-225153: 1   Max.   :2017-06-18  
##  (Other)  :86

Independence Day

##          stopID   stopDate
## 28222 17-247855 2017-07-04
## 28223 17-247866 2017-07-04
## 28224 17-247882 2017-07-04
## 28225 17-247899 2017-07-04
## 28226 17-247900 2017-07-04
## 28227 17-247903 2017-07-04
##        stopID       stopDate         
##  17-247855:  1   Min.   :2017-07-04  
##  17-247866:  1   1st Qu.:2017-07-04  
##  17-247882:  1   Median :2017-07-04  
##  17-247899:  1   Mean   :2017-07-04  
##  17-247900:  1   3rd Qu.:2017-07-04  
##  17-247903:  1   Max.   :2017-07-04  
##  (Other)  :127

Thanksgiving Day

##          stopID   stopDate
## 47547 17-447586 2017-11-23
## 47548 17-447589 2017-11-23
## 47549 17-447602 2017-11-23
## 47550 17-447604 2017-11-23
## 47551 17-447608 2017-11-23
## 47552 17-447616 2017-11-23
##        stopID      stopDate         
##  17-447586: 1   Min.   :2017-11-23  
##  17-447589: 1   1st Qu.:2017-11-23  
##  17-447602: 1   Median :2017-11-23  
##  17-447604: 1   Mean   :2017-11-23  
##  17-447608: 1   3rd Qu.:2017-11-23  
##  17-447616: 1   Max.   :2017-11-23  
##  (Other)  :88

Christmas Day

##          stopID   stopDate
## 51265 17-484316 2017-12-25
## 51266 17-484326 2017-12-25
## 51267 17-484331 2017-12-25
## 51268 17-484364 2017-12-25
## 51269 17-484394 2017-12-25
## 51270 17-484404 2017-12-25
##        stopID      stopDate         
##  17-484316: 1   Min.   :2017-12-25  
##  17-484326: 1   1st Qu.:2017-12-25  
##  17-484331: 1   Median :2017-12-25  
##  17-484364: 1   Mean   :2017-12-25  
##  17-484394: 1   3rd Qu.:2017-12-25  
##  17-484404: 1   Max.   :2017-12-25  
##  (Other)  :43

Let’s look at the annual average number of stops, and the stops for each holiday.

##           dates stopsPerDate
## 1 Anual Average     142.2466
## 2      New Year      88.0000
## 3        Mother     113.0000
## 4      Memorial     113.0000
## 5        Father      92.0000
## 6  Independence     133.0000
## 7  Thanksgiving      94.0000
## 8     Christmas      49.0000

In conclusion, the data shows that the number of stops in Minneapolis by the police department in 2017 are spread evenly throughout the year, but the number of stops is less than average on holidays.