[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"doc-seo-269316-105":3,"detail-sidebar-cat-0-en-105":81,"doc-detail-269316-en":131},{"code":4,"msg":5,"data":6},0,"ok",{"site_id":7,"language":8,"slug":9,"title":10,"keywords":11,"description":12,"schema_data":13,"social_meta":74,"head_meta":76,"extra_data":78,"updated_unix":80},105,"en","vehicle-emissions-and-smog-checks-with-a-changing-fleet-regulatory-program-effectiveness-over-time","Vehicle Emissions and Smog Checks with a Changing Fleet - Regulatory Program Effectiveness Over Time","","Many regional and local governments implement inspection and maintenance (I/M) programs to cut pollution from personal vehicles, yet their air-quality impact over time is unclear. The study estimates the contemporaneous effect of emissions inspections in California using within-county variation in the number of vehicles certified after failing an initial test. Older-vehicle reinspections reduce CO, NOx, and particulate matter, while reinspections for newer vehicles show no economically significant effects. This indicates that current biannual inspections matter less as older polluting fleets exit.",{"@graph":14,"@context":73},[15,34,56],{"@type":16,"itemListElement":17},"BreadcrumbList",[18,23,27,31],{"item":19,"name":20,"@type":21,"position":22},"https://docshare.wps.com","Home","ListItem",1,{"item":24,"name":25,"@type":21,"position":26},"https://docshare.wps.com/document/","Document",2,{"item":28,"name":29,"@type":21,"position":30},"https://docshare.wps.com/document/research-report/","Research & Report",3,{"item":32,"name":10,"@type":21,"position":33},"https://docshare.wps.com/document/vehicle-emissions-and-smog-checks-with-a-changing-fleet-regulatory-program-effectiveness-over-time/269316/",4,{"url":32,"name":10,"@type":35,"image":36,"author":41,"headline":10,"publisher":44,"fileFormat":47,"inLanguage":8,"description":12,"dateModified":48,"datePublished":49,"encodingFormat":47,"isAccessibleForFree":50,"interactionStatistic":51},"DigitalDocument",{"url":37,"@type":38,"width":39,"height":40},"https://docshare.wps.com/thumbnails/vehicle-emissions-and-smog-checks-with-a-changing-fleet-regulatory-program-effectiveness-over-time/269316.png","ImageObject",300,407,{"name":42,"@type":43},"Lucas Martin","Person",{"url":19,"name":45,"@type":46},"DocShare","Organization","application/pdf","2026-10-27","2026-09-15",true,{"@type":52,"interactionType":53,"userInteractionCount":55},"InteractionCounter",{"@type":54},"ViewAction",15,{"@type":57,"mainEntity":58},"FAQPage",[59,65,69],{"name":60,"@type":61,"acceptedAnswer":62},"What question does the study address about inspection and maintenance (I/M) programs?","Question",{"text":63,"@type":64},"The study tests whether I/M inspections are linked to local air pollution levels, estimating the contemporaneous effect of inspections on air quality in California.","Answer",{"name":66,"@type":61,"acceptedAnswer":67},"How does the paper proxy emissions-related repairs in California?",{"text":68,"@type":64},"It uses day-to-day, within-county variation in the number of vehicles certified after failing an initial emissions inspection as a proxy for emissions-related repairs.",{"name":70,"@type":61,"acceptedAnswer":71},"What are the main findings for older versus newer vehicles?",{"text":72,"@type":64},"Reinspections of older vehicles with less advanced emissions technology reduce local CO, NOx, and particulate matter, while reinspections of newer vehicles show no economically significant effect.","https://schema.org",{"og:url":32,"og:type":75,"og:title":10,"og:site_name":45,"og:description":12},"article",{"robots":77,"canonical":32},"index,follow",{"doc_id":79,"site_id":7},269316,1789450197,{"code":4,"msg":82,"data":83},"success",[84,88,92,96,101,106,111,115,120,123,127],{"id":22,"doc_module":4,"doc_module_name":25,"category_name":85,"show_sort_weight":86,"slug":87},"Story & Novel",90,"story-novel",{"id":26,"doc_module":4,"doc_module_name":25,"category_name":89,"show_sort_weight":90,"slug":91},"Literature",80,"literature",{"id":33,"doc_module":4,"doc_module_name":25,"category_name":93,"show_sort_weight":94,"slug":95},"Exam",70,"exam",{"id":97,"doc_module":4,"doc_module_name":25,"category_name":98,"show_sort_weight":99,"slug":100},5,"Comic",60,"comic",{"id":102,"doc_module":4,"doc_module_name":25,"category_name":103,"show_sort_weight":104,"slug":105},6,"Technology",50,"technology",{"id":107,"doc_module":4,"doc_module_name":25,"category_name":108,"show_sort_weight":109,"slug":110},7,"Healthcare",40,"healthcare",{"id":112,"doc_module":4,"doc_module_name":25,"category_name":29,"show_sort_weight":113,"slug":114},8,30,"research-report",{"id":116,"doc_module":4,"doc_module_name":25,"category_name":117,"show_sort_weight":118,"slug":119},9,"Religion & Spirituality",20,"religion-spirituality",{"id":118,"doc_module":4,"doc_module_name":25,"category_name":121,"show_sort_weight":118,"slug":122},"World Cup","world-cup",{"id":124,"doc_module":4,"doc_module_name":25,"category_name":125,"show_sort_weight":124,"slug":126},10,"Lifestyle","lifestyle",{"id":128,"doc_module":4,"doc_module_name":25,"category_name":129,"show_sort_weight":97,"slug":130},19,"General","general",{"code":4,"msg":82,"data":132},{"doc_id":79,"user_id":133,"nickname":42,"user_avatar":134,"doc_module":4,"category_id":112,"category_name":29,"doc_title":10,"doc_description":12,"doc_content":135,"file_id":136,"file_url":137,"file_type":138,"file_size":139,"view_count":55,"is_deleted":4,"is_public":22,"is_downloadable":22,"audit_status":22,"page_count":140,"language":141,"language_code":8,"site_id":7,"html_lang":8,"table_of_contents":142,"faqs":143,"seo_title":144,"seo_description":12,"update_tm":80,"read_time":145,"preview_page_count":4},8796095360427,"https://ap-avatar.wpscdn.com/davatar_994ba38a5ba835b3df7d355c54d3ed8d","Technology and the Effectiveness of Regulatory Programs over Time: Vehicle Emissions and Smog Checks with a Changing Fleet  \nNicholas J. Sanders, Ryan Sandler  \nAbstract: Many regional and local governments across the United States (US), Europe, and Asia have inspection and maintenance (I/M) programs designed to reduce pollution from personal transportation. To test for a link between I/M and local air pollution levels, we estimate the contemporaneous effect of inspections on local air quality in the US state of California. We use day-to-day, within-county variation in the number of vehicles certified after failing an initial emissions inspection as a proxy for emissions-related repairs. Additional passed reinspections of older vehicles with inferior emissions technology (pre-1985 model year) reduce local carbon monoxide, nitrogen oxide, and particulate matter levels, but passed reinspections of newer vehicles with more modern engine technology have no economically significant effect on air pollution. This suggests that biannual emissions inspections as currently implemented will play less ofa role in reducing local air pollution as polluting vehicles from the1970sand 1980s leave the road.  \nJEL Codes: Q52, Q53, Q58  \nKeywords: pollution, emissions testing, regulation  \nDESPITE REGULATORY ADVANCEMENTS and improvements in engine technology, motor vehicles remain responsible for 75% of carbon monoxide (CO) emissions in the  \nNicholas J. Sanders is at Cornell University and the National Bureau of Economic Research ([njsanders@cornell.edu](njsanders@cornell.edu)). Ryan Sandler (corresponding author) is at the Consumer Financial Protection Bureau ([ryan.sandler@cfpb.gov](ryan.sandler@cfpb.gov)). We are grateful to Dan Hosken, Mark Jacobsen, Thomas Koch, Devesh Raval, Joseph Shapiro, and participants in the Economics brown bag atthe Federal Trade Commission, the ASSA annual meeting, the University of Chicago Public Policy and Economics Workshop, the University of Illinois at Urbana-Champaign, and Miami University, for helpful comments and suggestions. Any opinions in this paper are ours and do not necessarily reflect those of the Consumer Financial Protection Bureau.  \nDataverse data: [https://doi.org/10.7910/DVN/VZLUG4](https://doi.org/10.7910/DVN/VZLUG4)  \nReceived December 14, 2018; Accepted December 23, 2019; Published online March 24, 2020.  \nJAERE, volume 7, number 3. © 2020 by The Association of Environmental and Resource Economists. All rights reserved. 2333-5955/2020/0703-0006$10.00 [https://doi.org/10.1086/707954](https://doi.org/10.1086/707954)  \n588 Journal of the Association of Environmental and Resource Economists May 2020  \nUnited States and over 50% of nitrogen oxide (NOx) emissions.1 Governments in both developed and developing countries have tried a number of policies to reduce pollution from personal automobiles. Improving fuel standards can decrease emissions per mile driven, but such programs disproportionately impact low-income households and decrease average road safety (Jacobsen 2013a, 2013b). Driving restriction programs have varied success rates for reducing local pollution (Davis 2008; Wolff 2014; Simeonova et al. 2018). Scrappage programs, often referred to as “Cash for Clunkers,” can directly remove the dirtiest vehicles from the road, but such programs have substantial problems with adverse selection and may only slightly shift forward the timing of vehicle replacement (Mian and Sufi 2012; Sandler 2012; Li et al. 2013; Hoekstra et al. 2014).  \nInspection and maintenance programs (I/M), the focus of this paper, attempt to limit tailpipe emissions through regular inspections and repairs, without changing driving behavior or fleet composition. Such programs are costly to governments and individuals (Ando et al. 2000) and subject to potential fraud (Oliva 2015). Although mandated repairs of high-emitting vehicles often show reduced tailpipe emissions in a testing environment, there exists no large-scale analysis","cbCaio4VQDdHiDTA","https://ap.wps.com/l/cbCaio4VQDdHiDTA","pdf",1689069,32,"English","# Abstract\n## Regulatory context and research question\n## Data and identification strategy\n## Main findings and air-quality effects\n## Implications for smog-check effectiveness over time","[{\"question\":\"What question does the study address about inspection and maintenance (I/M) programs?\",\"answer\":\"The study tests whether I/M inspections are linked to local air pollution levels, estimating the contemporaneous effect of inspections on air quality in California.\"},{\"question\":\"How does the paper proxy emissions-related repairs in California?\",\"answer\":\"It uses day-to-day, within-county variation in the number of vehicles certified after failing an initial emissions inspection as a proxy for emissions-related repairs.\"},{\"question\":\"What are the main findings for older versus newer vehicles?\",\"answer\":\"Reinspections of older vehicles with less advanced emissions technology reduce local CO, NOx, and particulate matter, while reinspections of newer vehicles show no economically significant effect.\"}]","Vehicle Emissions and Smog Checks with a Changing Fleet - Regulatory Program Effectiveness Over Time | PDF",81]