Chi-Yang Chu, Daniel J. Henderson, and Le Wang, "The Robust
Relationship between US Food Aid and Civil Conflict", Journal of
Applied Econometrics, Vol 32, No. 5, 2017, 1027-1032.

There are two folders, each with a set of programs and data. One is
for the replication of the original results in Nunn and Qian (2014) (R
Code and Data (Tables 1-13) [Parametric Endogenous Estimation -
Replication]) and the other is for our results using the semiparametric
endogenous estimation procedures (R Code and Data (Tables 11-13)
[Semiparametric Endogenous Estimation]). In each folder, we further
include a file called "instruction.txt", which briefly describes our
data (.csv) and shows how to replicate our results using the R code
accompanying these files (our R code itself should be
self-explanatory). 

All of the data used in our analysis are taken directly from Nunn and
Qian (2014) available at
https://www.aeaweb.org/articles?id=10.1257/aer.104.6.1630. See their
paper for a more detailed description of the samples and the
definitions of relevant variables.

The file "appendix_abcd.pdf" contains all the additional appendices
(Appendices A-D).

Our data are obtained from Nunn and Qian (2014) and we keep the same 
names of variables as theirs, see their Stata codes and data for all the 
details. Here we provide csv data files. Note that changing the order of 
the variables in the data will cause the code not to work.

*****

Parametric:

To replicate a result, run the code in the order of the file names, 
e.g., 0_package_and_function, 1_data_processing, and 
2_parametric_estimation.

In Table 6, we provide separate data for each result in order to avoid 
lengthy coding of data processing.

In Tables 11-13, we provide separate data for each result in order to 
avoid lengthy coding of data processing. Tables 11-13 are put together 
because they share nearly the same code.

*****

Semiparametric:

To perform the Ullah (1985) test, run the code in the order of the file 
names, i.e., 0_package_and_function, 1_data_processing, and 
2_bootstrapped_ullah_test. Ozabaci, Henderson, and Su's (2014) 
three-step procedure can be performed the same way. In addition, we also 
provide a weak IV test and descriptive statistics of gradients, both of 
which are not reported in the paper. Note that 2_weak_iv_test and 
2_descriptive_statistics_of_gradients share 0_package_and_function and 
1_data_processing with 2_ohs_procedure. However, to avoid potential 
errors, please re-run 0_package_and_function and 1_data_processing when 
finishing a task and moving to another.