The Time Hoppers

In 1967, Doubleday published The Time Hoppers, a science fiction novel by American author Robert Silverberg. The story follows Joe Quellen, a 25th-century bureaucrat whose job is to look into "hoppers"—time travelers from the future whose appearances in earlier eras have been recorded for centuries. It also involves his brother-in-law, Norman Pomrath, an unemployed blue-collar worker who is eventually given a chance to travel back in time.

Quellen is a Class Seven bureaucrat on a heavily stratified, overcrowded Earth in the 25th century, governed by a single world government. People in lower classes, like his sister and brother-in-law (Classes Fourteen and Fifteen), are limited to a single room, with the shower fully exposed. Oxygen is rationed. Quellen himself has secretly secured a house in Africa, but if discovered, he would face severe punishment, as living space is extremely scarce.

Technology is highly advanced, including teleportation and time travel. At the story's start, Quellen’s superiors have learned that missing segments of the population have traveled to the past seeking a better life; they are unsure whether to be relieved at losing thousands of people or worried that the time travelers might alter history. Quellen is assigned to handle the situation.