Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Eliminating Systematic Bias from Difference-in-Differences Design: A
  Permutational Detrending Strategy   Since the initial work by Ashenfelter and Card in 1985, the use of
difference-in-differences (DID) study design has become widespread. However, as
pointed out in the literature, this popular quasi-experimental design also
suffers estimation bias and inference bias, which could be very serious in some
circumstances. In this study, we start by investigating potential sources of
systemic bias from the DID design. Via analyzing their impact on statistical
estimation and inference, we propose a remedy -- a permutational detrending
(PD) strategy -- to overcome the challenges in both the estimation bias and the
inference bias. We prove that the proposed PD DID method provides unbiased
point estimates, confidence interval estimates, and significance tests. We
illustrate its statistical proprieties using simulation experiments. We
demonstrate its practical utility by applying it to the clinical data EASE
(Elder-Friendly Approaches to the Surgical Environment) and the
social-economical data CPS (Current Population Survey). We discuss the
strengths and limitations of the proposed approach.

14
The categories of this paper are: math-ph
24
The categories of this paper are: dg-ga
33
The categories of this paper are: plasm-ph
32
The categories of this paper are: atom-ph
18
The categories of this paper are: econ
4
The categories of this paper are: cond-mat
35
The categories of this paper are: mtrl-th
20
The categories of this paper are: acc-phys
27
The categories of this paper are: comp-gas
6
The categories of this paper are: astro-ph
37
The categories of this paper are: supr-con
11
The categories of this paper are: hep-lat
22
The categories of this paper are: chao-dyn
1
The categories of this paper are: cs
2
The categories of this paper are: math
28
The categories of this paper are: alg-geom