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Merge pull request #107 from code4policy/over_it
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‎impacts.html‎

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@@ -182,45 +182,13 @@ <h3 class="block-title">Harvard</h3>
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<div class="method-banner">
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<button class="method-toggle" aria-expanded="false">What Are These Numbers?<span class="chev">▾</span></button>
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<div class="method-content" hidden>
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<ol>
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<li>
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<strong>Step 1:</strong> Merge data sources to obtain key information
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<ul>
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<li>Data sources include the Massachusetts Department of Environmental Protection's Municipal Solid Waste and Recycling surveys from 2009 to 2024, inclusive; the Massachusetts Department of Revenue's Divison of Local Services; and the Massachusetts Department of Environmental Protection's spreadsheet, "Massachusetts Municipalities with PAYT Programs, June 2025".</li>
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<li>Key information: PAYT adoption year, years pre- and post-PAYT adoption, number of households enrolled in each municipality's trash system, annual tonnage disposed per household.</li>
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</ul>
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</li>
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<li>
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<strong>Step 2:</strong> Generate annual tons of waste disposed per household
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<ul>
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<li>Tons per household are calculated by dividing the municipality's total annual disposal tonnage by the number of households served by the PAYT program.</li>
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<li>Tons per household standardizes our metric, as larger municipalities will dispose of more total trash than smaller municipalities.</li>
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</ul>
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</li>
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<li>
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<strong>Step 3:</strong> Remove records that would distort the "normal trash" comparison
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<ul>
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<li>Keep only rows of data in which bulky waste is excluded.</li>
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<li>Exclude years that did not record yearly tonnage.</li>
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</ul>
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</li>
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<li>
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<strong>Step 4:</strong> Identify the longest pre- and post-period for parallel trends
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<ul>
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<li>Filter data to contain municipalities with data 5 years before implementing PAYT through 5 years after implementing PAYT.</li>
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<li>If one town has 20 years of data and another has 3 years, comparisons may not follow parallel trends; therefore, we may not conclude that adopting PAYT had a statistically significant result.</li>
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</ul>
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</li>
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<li>
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<strong>Step 5:</strong> Select Harvard, Chicopee, Heath, Hinsdale, and Peru
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</li>
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<li>
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<strong>Step 6:</strong> Create a time series chart
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<ul>
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<li><strong>IMPORTANT NOTE:</strong> Our time of adoption begins at -1 (the adoption year); Year 0 is the implementation year; Year 1 is one year after implementation.</li>
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</ul>
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</li>
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</ol>
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<h4>Terminology</h4>
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<ul style="margin-bottom: 20px;">
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<li><strong>Pre-PAYT Period:</strong> The years before a city started PAYT, showing how much trash households threw away normally.</li>
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<li><strong>Post-PAYT Period:</strong> The years after a city implemented PAYT, showing how much trash households threw away with the program.</li>
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<li><strong>Parallel Trends:</strong> Comparing cities with similar amounts of data before and after PAYT to ensure fair comparison.</li>
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<li><strong>Tons Per Household:</strong> The average amount of trash one household threw away each year, calculated for each city.</li>
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</ul>
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<p style="margin-top: 15px; font-size: 14px;">For more information on the methodology, visit the <a href="method.html">Methodology Tab</a>.</p>
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</div>
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</div>

‎method.html‎

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</div>
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</div>
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<div class="section-note">Pre-Post Effect of PAYT Within a 5-year Time Period</div>
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<strong>Step 1:</strong> Merge data sources to obtain key information
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<ul>
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<li>Data sources include the Massachusetts Department of Environmental Protection's Municipal Solid Waste and Recycling surveys from 2009 to 2024, inclusive; the Massachusetts Department of Revenue's Divison of Local Services; and the Massachusetts Department of Environmental Protection's spreadsheet, "Massachusetts Municipalities with PAYT Programs, June 2025".</li>
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<li>Key information: PAYT adoption year, years pre- and post-PAYT adoption, number of households enrolled in each municipality's trash system, annual tonnage disposed per household.</li>
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</ul>
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</li>
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<li>
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<strong>Step 2:</strong> Generate annual tons of waste disposed per household
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<ul>
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<li>Tons per household are calculated by dividing the municipality's total annual disposal tonnage by the number of households served by the PAYT program.</li>
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<li>Tons per household standardizes our metric, as larger municipalities will dispose of more total trash than smaller municipalities.</li>
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</ul>
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</li>
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<li>
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<strong>Step 3:</strong> Remove records that would distort the "normal trash" comparison
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<ul>
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<li>Keep only rows of data in which bulky waste is excluded.</li>
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<li>Exclude years that did not record yearly tonnage.</li>
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</ul>
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</li>
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<li>
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<strong>Step 4:</strong> Identify the longest pre- and post-period for parallel trends
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<ul>
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<li>Filter data to contain municipalities with data 5 years before implementing PAYT through 5 years after implementing PAYT.</li>
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<li>If one town has 20 years of data and another has 3 years, comparisons may not follow parallel trends; therefore, we may not conclude that adopting PAYT had a statistically significant result.</li>
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</ul>
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</li>
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<li>
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<strong>Step 5:</strong> Select Harvard, Chicopee, Heath, Hinsdale, and Peru
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</li>
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<li>
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<strong>Step 6:</strong> Create a time series chart
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<ul>
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<li><strong>IMPORTANT NOTE:</strong> Our time of adoption begins at -1 (the adoption year); Year 0 is the implementation year; Year 1 is one year after implementation.</li>
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</ul>
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</li>
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</div>
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</div>
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<script>
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(function () {
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function setBannerHeightVar() {

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