Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Confounding and Regression Adjustment in Difference-in-Differences   Difference-in-differences (diff-in-diff) is a study design that compares
outcomes of two groups (treated and comparison) at two time points (pre- and
post-treatment) and is widely used in evaluating new policy implementations.
For instance, diff-in-diff has been used to estimate the effect that increasing
minimum wage has on employment rates and to assess the Affordable Care Act's
effect on health outcomes. Although diff-in-diff appears simple, potential
pitfalls lurk. In this paper, we discuss one such complication: time-varying
confounding. We provide rigorous definitions for confounders in diff-in-diff
studies and explore regression strategies to adjust for confounding. In
simulations, we show how and when regression adjustment can ameliorate
confounding for both time-invariant and time-varying covariates. We compare our
regression approach to those models commonly fit in applied literature, which
often fail to address the time-varying nature of confounding in diff-in-diff.

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The categories of this paper are: nlin
30
The categories of this paper are: q-alg
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The categories of this paper are: bayes-an
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The categories of this paper are: acc-phys
10
The categories of this paper are: q-bio
25
The categories of this paper are: patt-sol
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The categories of this paper are: solv-int
1
The categories of this paper are: cs
19
The categories of this paper are: eess
0
The categories of this paper are: hep-ph
7
The categories of this paper are: hep-th
14
The categories of this paper are: math-ph
37
The categories of this paper are: supr-con
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The categories of this paper are: quant-ph
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The categories of this paper are: astro-ph
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The categories of this paper are: hep-lat