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.
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
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
Skated to work today for the first time since the pandemic.
January 15, 2025 at 4:55 PM
Our Monte Carlo simulations confirm the theoretical results: Standard TWFE, CS-DID, and FLEX, are biased when the two-way CCC is violated, while our DID-INT estimator is unbiased. Any comments are greatly appreciated. 5/5
December 20, 2024 at 4:11 PM
We define three types of CCC assumptions: state-invariant, time-invariant, and two-way CCC. Time-varying covariates are OK as long as we account for the specific CCC violations. We need to adapt the estimator to match the way that the covariates enter the DGP. 4/5
December 20, 2024 at 4:11 PM
We introduce a new estimator: (Two-Way) Intersection Difference-in-Differences (DID-INT), which provides unbiased estimates of the ATT even when CCC is violated. This approach can reveal parallel trends that are otherwise hidden. 3/5
December 20, 2024 at 4:11 PM
Existing DiD methods often assume that covariate effects are constant across groups and time, which we term the two-way CCC assumption. We show that when this assumption fails, both conventional TWFE and CS-DID estimators can be biased. 2/5
December 20, 2024 at 4:11 PM
Creating diagrams in tikz, with either text based or photo
based prompts.
November 16, 2024 at 12:41 AM
November 16, 2024 at 12:41 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