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An  NBER  volume edited by  Martin Feldstein  and Jeffrey Liebman called The Distributional Aspects of Social Security points out that members of racial minorities with lower than average life expectancies and lower than average rates of marriage may also suffer from the program on average .
 employee of: NBER, Martin Feldstein
Given a phrase that describes the relationship between two words, extract the words and the lexical relationship between them. The output format should be "relation1: word1, word2; relation2: word3, word4". 
Option: cities of residence, top members employees, members, alternate names, origin, state or provinces of residence, title of person, spouse, city of headquarters, NA, founded by, state or province of headquarters, employee of, countries of residence, country of birth, founded, subsidiaries, country of headquarters 
Text: {0} 
Answer:
 employee of: NBER, Martin Feldstein