Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Identification, Doubly Robust Estimation, and Semiparametric Efficiency
  Theory of Nonignorable Missing Data With a Shadow Variable
14
The categories of this paper are: math-ph
11
The categories of this paper are: hep-lat
10
The categories of this paper are: q-bio
5
The categories of this paper are: gr-qc
15
The categories of this paper are: nucl-ex
21
The categories of this paper are: adap-org
4
The categories of this paper are: cond-mat
20
The categories of this paper are: acc-phys
6
The categories of this paper are: astro-ph
29
The categories of this paper are: funct-an
2
The categories of this paper are: math
36
The categories of this paper are: cmp-lg
34
The categories of this paper are: chem-ph
30
The categories of this paper are: q-alg
25
The categories of this paper are: patt-sol
22
The categories of this paper are: chao-dyn