Joonho Phil Hwang
🏫 PhD student, Seoul National University
CV: Download PDF | Email: jhhwang24@snu.ac.kr
Hello. My name is Joonho Phil Hwang (황준호; 黃俊晧), and I am a fourth-year PhD student in economics at Seoul National University, where I am fortunate to be advised by Professor Seojeong Lee. My research interests are in econometrics, with a particular focus on
- panel data models
- causal inference
Working papers
Online Updating for Linear Panel Regressions
joint with Seojeong Lee
joint with Seojeong Lee
ABS
In this paper, we develop online updating methods for linear panel regression models.
Online updating refers to procedures for sequentially updating parameter estimates
as new data become available. In practice, the potential size of the dataset or data
confidentiality constraints may preclude researchers from storing or accessing the
entire dataset. We propose an online updating procedure for widely used linear
regression models in panel data, where data expansion can occur through either
(1) the arrival of new units or (2) the arrival of additional time periods for
existing units. The proposed procedure yields closed-form expressions for updating
both the point estimates and associated standard errors in each scenario.
What is online updating? See the example below:
What is online updating? See the example below:
presented at:
SNU Econometrics Workshop, SETA 2025, University of Sydney, KERIC 2025,
SNU Workshop on Recent Advances in Econometrics
On the Failure of the Bracketing Relationship in Staggered Treatment Designs
ABS
Applied researchers often face a dilemma regarding whether to include lagged dependent variables.
When the outcome exhibits state dependence but lagged terms are omitted, standard estimates can be biased.
Following Angrist and Pischke (2009), many rely on a “bracketing relationship”, treating specifications
with and without lagged outcomes as bounds for the true causal effect. In this paper, we demonstrate that
this heuristic breaks down in staggered two-way fixed effects settings.
Work in progress
Fixed Effects under Misspecification in Matched Panel Data