Table A2: Tests of sample selection

||Ana|lysis sa|mple|Lef|t-out sa|mple|Difer|ence|Joint|
|---|---|---|---|---|---|---|---|---|---|
||||||||||Test|
|Variable|N|Mean|Std.|N|Mean|Std.|Dif|Std.|F-stat.|
||||Err.|||Err.||Err.||
|Education group|||||||||1.502|
|Primary or below (dummy)|468|0.241|0.020|114|0.167|0.035|0.075|0.044||
|Secondary (dummy)|468|0.506|0.023|114|0.544|0.047|-0.037|0.052||
|Tertiary (dummy)|468|0.252|0.020|114|0.289|0.043|-0.037|0.046||
|Age group|||||||||3.067|
|15-24 years (dummy)|468|0.038|0.009|118|0.102|0.028|-0.063|0.023||
|20-24 years (dummy)|468|0.327|0.022|118|0.144|0.325|0.183|0.019||
|25-29 years (dummy)|468|0.368|0.022|118|0.432|0.046|-0.065|0.050||
|30-34 years (dummy)|468|0.162|0.017|118|0.169|0.035|-0.007|0.038||
|35-39 years (dummy)|468|0.058|0.011|118|0.093|0.027|-0.036|0.025||
|40-44 years (dummy)|468|0.019|0.006|118|0.034|0.017|-0.015|0.015||
|45-49 years (dummy)|468|0.009|0.004|118|0.008|0.008|0.000|0.009||
|50-54 years (dummy)|468|0.004|0.003|118|0.000|0.000|0.004|0.006||
|55-59 years (dummy)<br>|468|0.000|0.000|118|0.008|0.008|-0.008|0.004||
|60 or more years (dummy)|468|0.015|0.006|118|0.008|0.008|0.006|0.012||
|Occupation|||||||||0.715|
|Employer/Manager (dummy)|459|0.007|0.004|128|0.008|0.008|-0.001|0.008||
|Professional (dummy)|459|0.220|0.019|128|0.227|0.037|-0.007|0.042||
|Manual worker (dummy)|459|0.126|0.016|128|0.180|0.034|-0.053|0.034||
|Agricultural worker (dummy)|459|0.031|0.008|128|0.016|0.011|0.015|0.016||
|Military and security (dummy)|459|0.002|0.002|128|0.008|0.008|-0.006|0.006||
|Owner of a shop (dummy)|459|0.039|0.009|128|0.039|0.017|0.000|0.019||
|Government employee (dummy)|459|0.007|0.004|128|0.000|0.000|0.007|0.007||
|Private sector employee (dummy)|459|0.255|0.020|128|0.250|0.038|0.005|0.044||
|Craftsperson (dummy)|459|0.102|0.014|128|0.055|0.020|0.048|0.029||
|Illegal (dummy)|459|0.002|0.002|128|0.000|0.000|0.002|0.004||
|Student (dummy)|459|0.129|0.016|128|0.156|0.032|-0.028|0.034||
|Retired (dummy)|459|0.002|0.002|128|0.000|0.000|0.002|0.004||
|No work (dummy)|459|0.078|0.013|128|0.063|0.021|0.016|0.026||
|Civil Status|||||||||1.538|
|Divorced (dummy)|391|0.010|0.005|123|0.000|0.000|0.010|0.009||
|Married (dummy)|391|0.179|0.019|123|0.236|0.038|-0.057|0.041||
|Single (dummy)|391|0.811|0.020|123|0.764|0.038|0.047|0.041||
|Religious knowledge|||||||||1.230|
|Basic (dummy)|407|0.705|0.023|113|0.779|0.039|-0.074|0.048||
|Intermediary (dummy)|407|0.265|0.022|113|0.204|0.038|0.062|0.046||
|Advanced (dummy)|407|0.029|0.008|113|0.018|0.012|0.012|0.017||
|Experience with Jihad|||||||||0.161|
|No (dummy)|432|0.951|0.010|125|0.960|0.018|-0.009|0.021||
|Yes (dummy)|432|0.049|0.010|125|0.040|0.018|0.009|0.021||

_Notes:_ Variables are constructed from self-reported information provided by recruits that is available in the Daesh personnel records database. The “analysis” sample consists of observations included in the analysis; the “left-out” sample consists of observations dropped because of missing information on either delegation of residence, education, or age. In the last column, for each group of variables, the F-statistic reports the result of a test of joint significance of all variables in that group.

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