Short story about a man who realizes every day is a repeat of yesterday but no one else thinks so [duplicate]

Question

In 1988 I read a short story about a man who was on his way to work. He meets a friend at the bus stop and they engage in small talk, then get on the bus and go to work. They come home and go to sleep. The next morning, the guy goes out to the bus stop and meets his friend, and is surprised to hear his friend saying the exact same things he said the day before.

All day at work things happen exactly as they did the day before. The next morning is a repeat of the same, and he begins trying to get his friend to see that they are living in some kind of time loop, but his friend doesn't know what he's talking about.

The guy ends up staying home the next day, hiding in his house. Finally someone comes to his door and tells him he has been part of an experiment. Every night when they go to sleep their minds are erased. Scientists are observing behavior to see if in a given scenario there is any deviation in word or action if a person is subjected to the same stimuli repeatedly, if they have no knowledge of ever having done it before. For some reason, they forgot to erase his memory and he began remembering the previous days.

He doesn't believe what he is being told until he looks out the window and sees a giant in a lab coat. Turns out his house is just a small model on a train-type layout sitting on a table and he is one of many miniature "people" the scientists made to test their theories.

No idea who the author is or what the title was. I took a science fiction class in high school and this was one of the stories we had to read and then answer questions about.

Answer 1

Perhaps Frederick Pohl's The Tunnel Under the World? From Wikipedia's description (emphasis mine):

Guy and Mary Burckhardt wake up in their house in Tylerton on June 15, having both had terrible nightmares, but they can't recall the events of their dreams. Guy dismisses the dream and goes to work as usual, the downtown offices of Contro Chemicals, which operates a highly automated and robot-staffed petrochemicals plant. But something isn't right; he is surrounded everywhere by loud and all-pervasive advertising jingles for everything from cigarettes to freezers.

A colleague named Swanson tries to speak to him but apparently doesn't get the desired reaction from Burckhardt and leaves. Burckhardt goes home, but the next morning, when he wakes up, he's had the same nightmare and the date is still June 15th. He knows what will happen when he gets to the office and that Swanson will again try to speak to him. This in fact happens.

That evening, Burckhardt discovers that his cellar has seemingly been dismantled and 'rebuilt', in a way he doesn't recognise. And the next morning, again it's June 15th, although he knows it can't be. He mentions this when Swanson again tries to speak to him. Swanson hustles him away to the empty halls of the chemical plant. Hiding in a room at the end of a long tunnel, he explains his theory that they have all been tampered with and that an invader has taken over the town for unknown reasons.

But neither of them are correct. It transpires that the chemical plant exploded. All the inhabitants of Tylerton were killed by the explosion or the chemical fumes. Dorchin, a ruthless advertising executive, took over the whole ruins and rebuilt them in miniature. The people were rebuilt as minuscule robots, and are being used as captive subjects for testing high-pressure advertising campaigns.

The entire story is available at Project Gutenberg (thanks @Hypnosifl for the link).