蘑菇短视频

The success of distracted driving laws including cellphone bans on reducing traffic fatalities across the United States depends upon factors such as the comprehensiveness of deterrence strategies and the consistency of enforcement and fines.

That is among the findings of a 蘑菇短视频 College of Business faculty member鈥檚 analysis of how multiple state policies, goals and regulations combine and interact to address the national problem of vehicular accidents caused by the use of cellphones and other handheld devices while driving.

The study, titled 鈥淧olicy Instrument Mixes and Technology-Induced Externalities: Quasi-Experimental Evidence from U.S. Distracted Driving Laws,鈥� was led by Aaron Heinrich, 蘑菇短视频assistant professor of operations management.

Heinrich and his co-authors 鈥� Vipul Garg, assistant professor of supply chain management at Texas State University, and Trung Ho, a doctoral student at the University of North Texas 鈥� conducted the study over the summer through financial support from the College of Business Summer Research Grants Program, which awards grants to up to four faculty members each academic year.

Faculty submit proposals during the spring semester, and a committee of fellow faculty members, typically made up of past grant recipients, selects the winning proposals for the summer. Grant recipients are awarded $5,000 each to support their research and are expected to submit a proposal for conference presentation and then submit a written product of the research upon completion.

鈥淭he grant provided uninterrupted time during summer of 2026 that the project required,鈥� Heinrich said. 鈥淚 am grateful to the College of Business for providing financial support.鈥�

The Southwest Decision Sciences Institution has nominated the project for its 鈥淏est Regional Presentation Award.鈥� Heinrich has been invited to co-present the research findings at the DSI annual conference in San Francisco this November.

Heinrich and his colleagues spent the summer constructing a comprehensive record of states鈥� texting and handheld device bans, primary or secondary enforcement levels, effective ban dates and fine schedules. They then fine-tuned the record and audited it against statutory sources to develop a complete history of U.S. cellphone ban policy coverage from 1995 to 2019.

Next, the researchers formulated and tested several hypotheses, deriving their hypotheses from several sources including the policy framework itself and empirical deterrence literature. The work included the utilization of a five-estimator grid and exact randomization tests, permutation tests, minimum detectable effects, and event-study and sensitivity diagnostics to look at parallel trends.

Heinrich wrote the first draft of the manuscript, which was reviewed by a co-author with that feedback now being incorporated into a second draft for submission to a scholarly journal this fall.

The researchers widened the project鈥檚 scope as their analysis matured, Heinrich said. 鈥淎lthough my summer grant proposal targeted only the policy framework characteristic of consistency, our study now examines all four of the framework鈥檚 characteristics 鈥�  consistency, comprehensiveness, coherence and credibility,鈥� he said.

鈥淲e raise a question the literature has not yet asked 鈥� whether the four characteristics are empirically separable at all in policy domains containing few policy instruments,鈥� he said.

Heinrich and his colleagues found that the four characteristics are not fully separable. While comprehensiveness and coherence collapse onto a single dimension, in contrast the consistency and credibility characteristics are in fact separable, he said.

鈥淲e also find that the three empirical dimensions behave as a deterrence mechanism predicts. Comprehensive cellphone ban mix adoption reduces total traffic fatalities by roughly 5 percent. Consistency, which we measure as the alignment of enforcement levels across the policy mix, is associated with lower fatalities on every estimator and is conventionally significant on four of the five estimators,鈥� he said.

Four within-state events in which U.S. state legislators upgraded texting bans from secondary to primary enforcement corroborate this result, Heinrich said.

鈥淐redibility, which we measure as whether a U.S. state maintained the real value of its fine after adoption, shows no detectable effect, he said. 鈥淔ine levels and driver license points show no association with fatalities where deterrence predicts declines, and fatalities are higher where fines escalate, an association consistent with legislatures raising fines in response to bad fatality conditions rather than fines reducing fatalities.鈥�

Going forward, Heinrich and his co-investigators plan to outline and draft an online appendix, refine their panel entries and confirm two U.S. state entries against statutory documentation before re-running all of their primary and robustness analyses one final time. They are working toward submitting their study to the journal Research Policy this fall and presenting at a conference by Aug. 31, 2027.

Heinrich also will serve on next year鈥檚 selection committee for the 2027 round of College of Business Summer Research Grants.

Other 蘑菇短视频College of Business faculty members who received $5,000 in summer research money for 2026 are Dan Bradbury, assistant professor of marketing; Gary Curnutt, assistant professor of finance; and Christine Kirkland, assistant professor of management.