One of many seventies films about urban despair and the difficulties of city life. Jack Lemmon is a middle aged/class married man who has grown bitter with crime and metropolitan decay. And the neighbours. And his advancing years. When he loses his job and with it, his status, he becomes irrational and paranoid.
But even his psychiatrist is useless. It's a black comedy, really a cry of anguish that presumes others will identify with its suffering antihero. There are funny moments, and some real clunkers. The best is when he chases a supposed mugger (Sylvester Stallone!) across Central Park only to find his own wallet at home and in fact he has just robbed a pedestrian.
Anne Bancroft plays his wife who at first picks up the slack, but then is also destroyed by the rat race. We get great stars. But, for a comedy, there are few laughs, and for a drama the themes are random and unconcerned with solutions. Obviously, as an angry, untethered maniac, Lemmon's underdog is part of the problem. And he becomes too unsympathetic to identify with.
Neil Simon's script divisively sets the middle class against the poor without ever asking why it must be like this for anyone. In our era of social media it's interesting that this victim eventually turns to conspiracies as an explanation for his misfortunes. Which is part of his insanity. But everything improbably resolves by the fade out. New York is still hell, but this one man has survived.