Comparing harm-spots and hot-spots for crime analysis

.title[
# Comparing harm-spots and hot-spots for crime analysis
]
.author[
### Matt Ashby, University College London
]

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Which neighbourhood team should we allocate more officers to?

Which district should we prioritise for extra funding?

Which local politicians should we focus on working with?

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$$
\text{harm} = \sum ( \text{crimes of a type} \times \text{severity of that type} )
$$

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<table class="gt_table">
  
  <thead class="gt_col_headings">
    <tr>
      <th class="gt_center gt_columns_top_border gt_column_spanner_outer" rowspan="1" colspan="3">
        <span class="gt_column_spanner">Most common types of crime in the 100 grid cells with the most …</span>
      </th>
    </tr>
    <tr>
      <th class="gt_col_heading gt_columns_bottom_border gt_left" rowspan="1" colspan="1"></th>
      <th class="gt_col_heading gt_columns_bottom_border gt_left" rowspan="1" colspan="1">disproportionately high <em>crime counts</em></th>
      <th class="gt_col_heading gt_columns_bottom_border gt_left" rowspan="1" colspan="1">disproportionately high <em>harm</em></th>
    </tr>
  </thead>
  <tbody class="gt_table_body">
    <tr><td class="gt_row gt_left"><div class='gt_from_md'><p>1st</p>
</div></td>
<td class="gt_row gt_left" style="color: #832424;"><div class='gt_from_md'><p>Miscellaneous theft</p>
</div></td>
<td class="gt_row gt_left" style="color: #3A3A98;"><div class='gt_from_md'><p>Common assault and battery</p>
</div></td></tr>
    <tr><td class="gt_row gt_left"><div class='gt_from_md'><p>2nd</p>
</div></td>
<td class="gt_row gt_left" style="color: #832424;"><div class='gt_from_md'><p>Theft from a motor vehicle</p>
</div></td>
<td class="gt_row gt_left" style="color: #3A3A98;"><div class='gt_from_md'><p>Assaults occasioning actual bodily harm</p>
</div></td></tr>
    <tr><td class="gt_row gt_left"><div class='gt_from_md'><p>3rd</p>
</div></td>
<td class="gt_row gt_left" style="color: #832424;"><div class='gt_from_md'><p><strong>Theft from shops</strong></p>
</div></td>
<td class="gt_row gt_left" style="color: #3A3A98;"><div class='gt_from_md'><p>Theft from a motor vehicle</p>
</div></td></tr>
    <tr><td class="gt_row gt_left"><div class='gt_from_md'><p>4th</p>
</div></td>
<td class="gt_row gt_left" style="color: #832424;"><div class='gt_from_md'><p>Common assault and battery</p>
</div></td>
<td class="gt_row gt_left" style="color: #3A3A98;"><div class='gt_from_md'><p>Criminal damage</p>
</div></td></tr>
    <tr><td class="gt_row gt_left"><div class='gt_from_md'><p>5th</p>
</div></td>
<td class="gt_row gt_left" style="color: #832424;"><div class='gt_from_md'><p>Criminal damage</p>
</div></td>
<td class="gt_row gt_left" style="color: #3A3A98;"><div class='gt_from_md'><p>Other burglary in a dwelling</p>
</div></td></tr>
    <tr><td class="gt_row gt_left"><div class='gt_from_md'><p>6th</p>
</div></td>
<td class="gt_row gt_left" style="color: #832424;"><div class='gt_from_md'><p><strong>Stealing from the person of another</strong></p>
</div></td>
<td class="gt_row gt_left" style="color: #3A3A98;"><div class='gt_from_md'><p><strong>Sending letters etc. with intent to cause distress or anxiety</strong></p>
</div></td></tr>
    <tr><td class="gt_row gt_left"><div class='gt_from_md'><p>7th</p>
</div></td>
<td class="gt_row gt_left" style="color: #832424;"><div class='gt_from_md'><p><strong>Making off without payment</strong></p>
</div></td>
<td class="gt_row gt_left" style="color: #3A3A98;"><div class='gt_from_md'><p>Miscellaneous theft</p>
</div></td></tr>
    <tr><td class="gt_row gt_left"><div class='gt_from_md'><p>8th</p>
</div></td>
<td class="gt_row gt_left" style="color: #832424;"><div class='gt_from_md'><p>Assaults occasioning actual bodily harm</p>
</div></td>
<td class="gt_row gt_left" style="color: #3A3A98;"><div class='gt_from_md'><p>Theft of motor vehicle</p>
</div></td></tr>
    <tr><td class="gt_row gt_left"><div class='gt_from_md'><p>9th</p>
</div></td>
<td class="gt_row gt_left" style="color: #832424;"><div class='gt_from_md'><p>Other burglary in a dwelling</p>
</div></td>
<td class="gt_row gt_left" style="color: #3A3A98;"><div class='gt_from_md'><p><strong>Wound / inflict grievous bodily harm without intent</strong></p>
</div></td></tr>
    <tr><td class="gt_row gt_left"><div class='gt_from_md'><p>10th</p>
</div></td>
<td class="gt_row gt_left" style="color: #832424;"><div class='gt_from_md'><p>Theft of motor vehicle</p>
</div></td>
<td class="gt_row gt_left" style="color: #3A3A98;"><div class='gt_from_md'><p><strong>Robbery</strong></p>
</div></td></tr>
  </tbody>
  
  <tfoot class="gt_footnotes">
    <tr>
      <td class="gt_footnote" colspan="3"> offence types in <strong>bold</strong> only appear in one column</td>
    </tr>
  </tfoot>
</table>
</div>

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### Main points

The overall correlation between count and harm is high

The correlation in hotspots is lower, meaning high-harm places might be missed

Mapping based on counts largely ignores violent crime

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### Next steps

Are the findings similar using administrative areas?

What are the demographic characteristics of high-harm areas?

How stable are high-harm areas?

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These slides:<br>
<b>http://lesscrime.info/slides/ecca-2022</b>

Questions/comments:<br>
<b>matthew.ashby@ucl.ac.uk</b>