IDEAS home Printed from https://ideas.repec.org/p/arx/papers/2309.05639.html

Forecasted Treatment Effects

Author

Listed:
  • Irene Botosaru
  • Raffaella Giacomini
  • Martin Weidner

Abstract

We consider estimation and inference of the effects of a policy in the absence of an untreated or control group. We obtain unbiased estimators of individual (heterogeneous) treatment effects and a consistent and asymptotically normal estimator of the average treatment effect. Our estimator averages, across individuals, the difference between observed post-treatment outcomes and unbiased forecasts of their counterfactuals, based on a (short) time series of pre-treatment data. The paper emphasizes the importance of focusing on forecast unbiasedness rather than accuracy when the end goal is estimation of average treatment effects. We show that simple basis function regressions ensure forecast unbiasedness for a broad class of data generating processes for the counterfactuals. In contrast, forecasting based on a specific parametric model requires stronger assumptions and is prone to misspecification and estimation bias. We show that our method can replicate the findings of some previous empirical studies but it does so without using an untreated or control group.

Suggested Citation

  • Irene Botosaru & Raffaella Giacomini & Martin Weidner, 2023. "Forecasted Treatment Effects," Papers 2309.05639, arXiv.org, revised Jan 2026.
    • Handle: RePEc:arx:papers:2309.05639
    as

    Download full text from publisher

    File URL: http://arxiv.org/pdf/2309.05639
    File Function: Latest version
    Download Restriction: no
    ---><---

    References listed on IDEAS

    as
    1. Gallego, Francisco & Montero, Juan-Pablo & Salas, Christian, 2013. "The effect of transport policies on car use: A bundling model with applications," Energy Economics, Elsevier, vol. 40(S1), pages 85-97.
    2. Marc K. Chan & Simon S. Kwok, 2022. "The PCDID Approach: Difference-in-Differences When Trends Are Potentially Unparallel and Stochastic," Journal of Business & Economic Statistics, Taylor & Francis Journals, vol. 40(3), pages 1216-1233, June.
    3. Victor Chernozhukov & Iván Fernández‐Val & Jinyong Hahn & Whitney Newey, 2013. "Average and Quantile Effects in Nonseparable Panel Models," Econometrica, Econometric Society, vol. 81(2), pages 535-580, March.
    4. Xu, Yiqing, 2017. "Generalized Synthetic Control Method: Causal Inference with Interactive Fixed Effects Models," Political Analysis, Cambridge University Press, vol. 25(1), pages 57-76, January.
    5. Tu, Meng & Zhang, Bing & Xu, Jianhua & Lu, Fangwen, 2020. "Mass media, information and demand for environmental quality: Evidence from the “Under the Dome”," Journal of Development Economics, Elsevier, vol. 143(C).
    6. Gallego, Francisco & Montero, Juan-Pablo & Salas, Christian, 2013. "The effect of transport policies on car use: Evidence from Latin American cities," Journal of Public Economics, Elsevier, vol. 107(C), pages 47-62.
    7. Nelson, Charles R. & Plosser, Charles I., 1982. "Trends and random walks in macroeconmic time series : Some evidence and implications," Journal of Monetary Economics, Elsevier, vol. 10(2), pages 139-162.
    8. 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.
    Full references (including those not matched with items on IDEAS)

    Citations

    Citations are extracted by the CitEc Project, subscribe to its RSS feed for this item.
    as


    Cited by:

    1. Dubé, Jean & Le Gallo, Julie & Des Rosiers, François & Legros, Diègo & Champagne, Marie-Pier, 2024. "An integrated causal framework to evaluate uplift value with an example on change in public transport supply," Transportation Research Part E: Logistics and Transportation Review, Elsevier, vol. 185(C).

    Most related items

    These are the items that most often cite the same works as this one and are cited by the same works as this one.
    1. Nicholas Brown & Kyle Butts & Joakim Westerlund, 2023. "Simple Difference-in-Differences Estimation in Fixed-T Panels," Papers 2301.11358, arXiv.org, revised Jun 2023.
    2. Hugo Freeman & Martin Weidner, 2021. "Low-rank approximations of nonseparable panel models," The Econometrics Journal, Royal Economic Society, vol. 24(2), pages 40-77.
    3. Dmitry Arkhangelsky & Guido Imbens, 2023. "Causal Models for Longitudinal and Panel Data: A Survey," Papers 2311.15458, arXiv.org, revised Jun 2024.
    4. Salgado, Edgar & Mitnik, Oscar A., 2021. "Spatial and Time Spillovers of Driving Restrictions: Causal Evidence from Limas Pico y Placa Policy," IDB Publications (Working Papers) 11818, Inter-American Development Bank.
    5. Sarmiento, Luis & Wägner, Nicole & Zaklan, Aleksandar, 2023. "The air quality and well-being effects of low emission zones," Journal of Public Economics, Elsevier, vol. 227(C).
    6. Iv'an Fern'andez-Val & Hugo Freeman & Martin Weidner, 2020. "Low-Rank Approximations of Nonseparable Panel Models," Papers 2010.12439, arXiv.org, revised Mar 2021.
    7. Luis Sarmiento & Nicole Wägner & Aleksandar Zaklan, 2021. "Effectiveness, Spillovers, and Well-Being Effects of Driving Restriction Policies," Discussion Papers of DIW Berlin 1947, DIW Berlin, German Institute for Economic Research.
    8. Wu, Libo & Zhou, Yang, 2025. "Social norms and energy conservation in China," Resource and Energy Economics, Elsevier, vol. 82(C).
    9. Caplan, Arthur J. & Acharya, Ramjee, 2019. "Optimal vehicle use in the presence of episodic mobile-source air pollution," Resource and Energy Economics, Elsevier, vol. 57(C), pages 185-204.
    10. Hao, Shiming, 2021. "True structure change, spurious treatment effect? A novel approach to disentangle treatment effects from structure changes," MPRA Paper 108679, University Library of Munich, Germany.
    11. Soto, Jose J. & Macea, Luis F. & Cantillo, Victor, 2023. "Analysing a license plate-based vehicle restriction policy with optional exemption charge: The case in Cali, Colombia," Transportation Research Part A: Policy and Practice, Elsevier, vol. 170(C).
    12. Magalhães, David José Ahouagi Vaz de & Rivera-Gonzalez, Carlos, 2021. "Car users’ attitudes towards an enhanced bus system to mitigate urban congestion in a developing country," Transport Policy, Elsevier, vol. 110(C), pages 452-464.
    13. Ludlow, Timothy & Fooken, Jonas & Rose, Christiern & Tang, Kam Ki, 2025. "Housing insecurity, financial hardship and mental health," Economics & Human Biology, Elsevier, vol. 57(C).
    14. Catherine Hausman & David S. Rapson, 2018. "Regression Discontinuity in Time: Considerations for Empirical Applications," Annual Review of Resource Economics, Annual Reviews, vol. 10(1), pages 533-552, October.
    15. Hans-Bernd Schaefer & Rok Spruk, 2024. "Islamic Law, Western European Law and the Roots of Middle East's Long Divergence: a Comparative Empirical Investigation (800-1600)," Papers 2401.14435, arXiv.org, revised Mar 2024.
    16. repec:osf:socarx:3mfzq_v1 is not listed on IDEAS
    17. Guo, Xue & Cheng, Aaron & Pavlou, Paul A., 2025. "Skill-biased technical change, again? Online gig platforms and local employment," LSE Research Online Documents on Economics 124538, London School of Economics and Political Science, LSE Library.
    18. Rafaty, Ryan & Dolphin, Geoffroy & Pretis, Felix, 2025. "Carbon pricing and the elasticity of CO2 emissions," Energy Economics, Elsevier, vol. 144(C).
    19. Cl'ement de Chaisemartin & Xavier D'Haultf{oe}uille, 2025. "Treatment-Effect Estimation in Complex Designs under a Parallel-trends Assumption," Papers 2508.07808, arXiv.org, revised Dec 2025.
    20. Ryan Rafaty & Geoffroy Dolphin & Felix Pretis, 2020. "Carbon pricing and the elasticity of CO2 emissions," Working Papers EPRG2035, Energy Policy Research Group, Cambridge Judge Business School, University of Cambridge.
    21. Tao Zhang & Yibo Yan & Qi Chen & Ze Liu, 2022. "Evaluation Method of Composite Development Bus Terminal Using Multi-Source Data Processing," Land, MDPI, vol. 11(10), pages 1-14, October.

    More about this item

    NEP fields

    This paper has been announced in the following NEP Reports:

    Statistics

    Access and download statistics

    Corrections

    All material on this site has been provided by the respective publishers and authors. You can help correct errors and omissions. When requesting a correction, please mention this item's handle: RePEc:arx:papers:2309.05639. See general information about how to correct material in RePEc.

    If you have authored this item and are not yet registered with RePEc, we encourage you to do it here. This allows to link your profile to this item. It also allows you to accept potential citations to this item that we are uncertain about.

    If CitEc recognized a bibliographic reference but did not link an item in RePEc to it, you can help with this form .

    If you know of missing items citing this one, you can help us creating those links by adding the relevant references in the same way as above, for each refering item. If you are a registered author of this item, you may also want to check the "citations" tab in your RePEc Author Service profile, as there may be some citations waiting for confirmation.

    For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: arXiv administrators (email available below). General contact details of provider: http://arxiv.org/ .

    Please note that corrections may take a couple of weeks to filter through the various RePEc services.

    IDEAS is a RePEc service. RePEc uses bibliographic data supplied by the respective publishers.