Harold Greenwald, a psychotherapist whose doctoral dissertation on the psychology of prostitutes evolved into a best-selling 1958 book, ''The Call Girl,'' and a Hollywood movie, ''Girl of the Night,'' died on Friday at his home in Santa Monica, Calif. He was 88.

Though Dr. Greenwald was best known by the public for his studies of prostitutes, his reputation among psychologists stemmed largely from his development of direct decision therapy, an offshoot of rational emotive behavior therapy.

''What he founded was the opposite of psychoanalysis, which is what he started in,'' said Albert Ellis, the Manhattan psychologist who developed rational emotive behavior therapy. ''He said you make a decision to upset yourself; you don't get upset because of something that happened in your childhood.''

Dr. Greenwald was born on July 28, 1910, in Manhattan. After graduating from the City College of New York in 1933, he worked for the city housing authority and the city planning board. During World War II, he was a civilian instructor for the Army Air Forces.

http://www.nytimes.com/1999/04/02/us/harold-greenwald-88-expert-on-psychology-of-prostitutes.html