Matt Webb
mattdwebb.bsky.social
Matt Webb
@mattdwebb.bsky.social
Associate Professor of Economics at Carleton University. Interested in statistical inference, empirical micro, and experiments.
Looking forward to Celebrating @James MacKinnon next week in Kingston.

Friday, September 12th is the last day to register, you can do that here:
events.fin.queensu.ca/cgi/registra...

The program is available here:
docs.google.com/document/d/1...

Hope to see you there. 1/2
events.fin.queensu.ca
September 12, 2025 at 11:19 AM
Excited to be a part of a special issue of the Canadian Journal of Economics in honour of James MacKinnon, this complements the conference being held in Kingston on September 18-19. Please consider submitting your papers to both the conference and the special issue. 1/3
June 6, 2025 at 2:09 PM
Excited to open the call for papers for the 40th Canadian Econometric Study Group (CESG) conference. The conference will be in Ottawa from October 17 to October 19, this year's theme is `Credible Econometrics'. For more details, see caneconometrics.ca/annualMeetin...
#econtwitter #cdnecon
May 27, 2025 at 8:12 PM
​I'm thrilled that our boottest article recently surpassed 1000 citations. This is beyond what we ever expected. To celebrate, I’ll highlight two new features added since the article was published. The first concerns speed, the second reliability. #econTwitter 1/4
May 14, 2025 at 1:18 PM
TFW you threaten to fire the Governor of the Bank of Canada and a former Governor takes your job.
April 29, 2025 at 1:05 PM
Are you going to the CEA 2025 conference in Montreal? Do you play hockey? Lanny Zrill and I are organizing the second annual ice hockey game.

The game takes place on Thursday, May 29th from 17h00-17h50.

To join us please email ceahockey@gmail.com for more details. #cdnecon #econtwitter
April 4, 2025 at 8:36 PM
Reposted by Matt Webb
The second edition of The Effect is now available for preorder! This version has a whole new chapter on Partial Identification, a considerable update on staggered treatment and control variables in DID, and zillions of other little updates throughout. www.routledge.com/The-Effect-A...
The Effect: An Introduction to Research Design and Causality
The Effect: An Introduction to Research Design and Causality, Second edition is about research design, specifically concerning research that uses observational data to make a causal inference. It is s...
www.routledge.com
April 1, 2025 at 6:17 PM
Skated to work today for the first time since the pandemic.
January 15, 2025 at 4:55 PM
Excited to share my latest work with​ @sunnykarimcu.bsky.social on Difference-in-Differences with time-varying covariates. We introduce the common causal covariates (CCC) assumption and show how its violation biases DiD estimators. Check it out! arxiv.org/abs/2412.14447 1/5
Good Controls Gone Bad: Difference-in-Differences with Covariates
This paper introduces the two-way common causal covariates (CCC) assumption, which is necessary to get an unbiased estimate of the ATT when using time-varying covariates in existing Difference-in-Diff...
arxiv.org
December 20, 2024 at 4:11 PM
The Canadian government recently expanded the list of banned firearms. Do municipalities with more licensed firearm owners, or registered firearms, experience more firearm deaths or crimes? Essentially, no. See our recent paper here: github.com/mattdwebb/CD... #cdnpoli 1/
github.com
December 7, 2024 at 3:15 PM
Welcome to all my new followers. I suspect many of you will be underwhelmed by my irregular posts about hypothesis testing and causal inference.
We need a word for "Sorry if you followed me from a starter pack and weren't expecting this"
November 19, 2024 at 4:15 AM
After nearly two years of working with chatGPT I'm still in awe. A quick thread of capabilities I've found useful for teaching and research.

Converting photos of (poorly) handwritten notes into beamer slides:
November 16, 2024 at 12:41 AM
Reposted by Matt Webb
So excited to announce that our textbook with Xavier, "Difference-in-Differences for Simple and Complex Natural Experiments", is now under contract with Princeton University Press. Check out the "working textbook" version here! Comments welcome! papers.ssrn.com/sol3/papers....
December 14, 2023 at 12:33 PM
Reposted by Matt Webb
100x performance improvement for the Callaway-Sant'Anna DiD estimator. Super impressive. github.com/TsaiLintung/...

#EconSky
November 29, 2023 at 5:05 PM