But Glaeser has many admirers , and several research collaborators , on the liberal end of the spectrum ; he likewise displays an odd enthusiasm for progressive efforts like those by London 's mayor , Ken Livingstone -LRB- Glaeser affectionately calls him by his popular nickname , Red Ken -RRB- , who imposed a stringent '' traffic tax '' on vehicles in the center city to reduce congestion .
Ken Livingstone /people/person/place_lived London
CC NNP VBZ JJ NNS , CC JJ NN NNS , IN DT JJ NN IN DT NN : PRP RB VBZ DT JJ NN IN JJ NNS IN DT IN NNP POS NN , NNP NNP -LRB- NNP RB VBZ PRP IN PRP$ JJ NN , NNP NNP -RRB- , WP VBD DT JJ '' NN NN '' IN NNS IN DT NN NN TO VB NN .
Ken Livingstone
PERSON
London
LOCATION
/people/person/place_lived