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Difference-in-Differences in the Presence of Unknown Interference

Author

Listed:
  • Fabrizia Mealli
  • Javier Viviens

Abstract

The stable unit treatment value (SUTVA) is a crucial assumption in the Difference-in-Differences (DiD) research design. It rules out hidden versions of treatment and any sort of interference and spillover effects across units. Even if this is a strong assumption, it has not received much attention from DiD practitioners and, in many cases, it is not even explicitly stated as an assumption, especially the no-interference assumption. In this technical note, we investigate what the DiD estimand identifies in the presence of unknown interference. We show that the DiD estimand identifies a contrast of causal effects, but it is not informative on any of these causal effects separately, without invoking further assumptions. Then, we explore different sets of assumptions under which the DiD estimand becomes informative about specific causal effects. We illustrate these results by revisiting the seminal paper on minimum wages and employment by Card and Krueger (1994).

Suggested Citation

  • Fabrizia Mealli & Javier Viviens, 2025. "Difference-in-Differences in the Presence of Unknown Interference," Papers 2512.21176, arXiv.org, revised Feb 2026.
    • Handle: RePEc:arx:papers:2512.21176
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    References listed on IDEAS

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    1. Goodman-Bacon, Andrew, 2021. "Difference-in-differences with variation in treatment timing," Journal of Econometrics, Elsevier, vol. 225(2), pages 254-277.
    2. Daniel Kuehn, 2016. "Spillover Bias in Cross-Border Minimum Wage Studies: Evidence from a Gravity Model," Journal of Labor Research, Springer, vol. 37(4), pages 441-459, December.
    3. Shirley, Peter, 2018. "The response of commuting patterns to cross-border policy differentials: Evidence from the American Community Survey," Regional Science and Urban Economics, Elsevier, vol. 73(C), pages 1-16.
    4. Doruk Cengiz & Arindrajit Dube & Attila Lindner & Ben Zipperer, 2019. "The Effect of Minimum Wages on Low-Wage Jobs," The Quarterly Journal of Economics, President and Fellows of Harvard College, vol. 134(3), pages 1405-1454.
    5. Qiaoyi Chen & Zhao Chen & Zhikuo Liu & Juan Carlos Suárez Serrato & Daniel Yi Xu, 2025. "Regulating Conglomerates: Evidence from an Energy Conservation Program in China," American Economic Review, American Economic Association, vol. 115(2), pages 408-447, February.
    6. Laura Forastiere & Edoardo M. Airoldi & Fabrizia Mealli, 2021. "Identification and Estimation of Treatment and Interference Effects in Observational Studies on Networks," Journal of the American Statistical Association, Taylor & Francis Journals, vol. 116(534), pages 901-918, April.
    7. Martin Huber & Eva-Maria Oe{ss}, 2024. "A joint test of unconfoundedness and common trends," Papers 2404.16961, arXiv.org, revised Jun 2024.
    8. Dmitry Arkhangelsky & Guido Imbens, 2023. "Causal Models for Longitudinal and Panel Data: A Survey," Papers 2311.15458, arXiv.org, revised Jun 2024.
    9. Dalia Ghanem & Pedro H. C. Sant'Anna & Kaspar Wüthrich, 2022. "Selection and Parallel Trends," CESifo Working Paper Series 9910, CESifo.
    10. Dmitry Arkhangelsky & Guido Imbens, 2024. "Causal models for longitudinal and panel data: a survey," The Econometrics Journal, Royal Economic Society, vol. 27(3), pages 1-61.
    11. Luca Braghieri & Ro'ee Levy & Alexey Makarin, 2022. "Social Media and Mental Health," American Economic Review, American Economic Association, vol. 112(11), pages 3660-3693, November.
    12. Jean Baldwin Grossman, 1983. "The Impact of the Minimum Wage on Other Wages," Journal of Human Resources, University of Wisconsin Press, vol. 18(3), pages 359-378.
    13. Ashesh Rambachan & Jonathan Roth, 2023. "A More Credible Approach to Parallel Trends," The Review of Economic Studies, Review of Economic Studies Ltd, vol. 90(5), pages 2555-2591.
    14. Imbens,Guido W. & Rubin,Donald B., 2015. "Causal Inference for Statistics, Social, and Biomedical Sciences," Cambridge Books, Cambridge University Press, number 9780521885881, November.
    15. Francesca Truffa & Ashley Wong, 2025. "Undergraduate Gender Diversity and the Direction of Scientific Research," American Economic Review, American Economic Association, vol. 115(7), pages 2414-2448, July.
    16. McKinnish, Terra, 2017. "Cross-state differences in the minimum wage and out-of-state commuting by low-wage workers," Regional Science and Urban Economics, Elsevier, vol. 64(C), pages 137-147.
    17. Sun, Liyang & Abraham, Sarah, 2021. "Estimating dynamic treatment effects in event studies with heterogeneous treatment effects," Journal of Econometrics, Elsevier, vol. 225(2), pages 175-199.
    18. Callaway, Brantly & Sant’Anna, Pedro H.C., 2021. "Difference-in-Differences with multiple time periods," Journal of Econometrics, Elsevier, vol. 225(2), pages 200-230.
    19. Ekaterina Jardim & Mark C. Long & Robert Plotnick & Emma van Inwegen & Jacob Vigdor & Hilary Wething, 2022. "Minimum-Wage Increases and Low-Wage Employment: Evidence from Seattle," American Economic Journal: Economic Policy, American Economic Association, vol. 14(2), pages 263-314, May.
    20. Alessandra Fenizia & Raffaele Saggio, 2024. "Organized Crime and Economic Growth: Evidence from Municipalities Infiltrated by the Mafia," American Economic Review, American Economic Association, vol. 114(7), pages 2171-2200, July.
    21. Jonathan Roth & Pedro H. C. Sant'Anna, 2023. "When Is Parallel Trends Sensitive to Functional Form?," Econometrica, Econometric Society, vol. 91(2), pages 737-747, March.
    22. Kyle Butts, 2021. "Difference-in-Differences Estimation with Spatial Spillovers," Papers 2105.03737, arXiv.org, revised Jun 2023.
    23. Card, David & Krueger, Alan B, 1994. "Minimum Wages and Employment: A Case Study of the Fast-Food Industry in New Jersey and Pennsylvania," American Economic Review, American Economic Association, vol. 84(4), pages 772-793, September.
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