3) The gap between the productivity of women and the productivity of men.
( ( 3 -RRB- ) ( ( ( ( ( The gap ) ( between ( the productivity ) ) ) ( of ( ( women and ) ( the productivity ) ) ) ) ( of men ) ) . ) )
(ROOT (NP (LST (LS 3) (-RRB- -RRB-)) (NP (DT The) (NN gap)) (PP (IN between) (NP (DT the) (NN productivity))) (PP (IN of) (NP (NP (NNS women)) (CC and) (NP (DT the) (NN productivity)))) (PP (IN of) (NP (NNS men))) (. .)))
The gap of genders.
( ( ( The gap ) ( of genders ) ) . )
(ROOT (NP (NP (DT The) (NN gap)) (PP (IN of) (NP (NNS genders))) (. .)))