According to Wikipedia, “The parable of the broken window was introduced by French economist Frédéric Bastiat in his 1850 essay “That Which Is Seen, and That Which Is Not Seen” to illustrate why destruction, and the money spent to recover from destruction, is not actually a net benefit to society.”
The broken window fallacy was supposed to explain the things seen and the things not seen. If someone breaks a window, the owner must use his money to replace the window. That is the thing seen. What about the thing not seen? If the window was never broken, what would the owner of the window would have used the money that was supposed to replace the broken window on? The owner of the broken window would have used that money on something else, but he had to use it on the broken window. That is the thing not seen. What the owner would have used his money on if the window was never broken.
This happens all the time in different examples, but it is the same fallacy. People argue that building a bridge, for example, creates jobs, therefore helping people. And it does help people get jobs. However, what would have the money used on the bridge be used for if the bridge was never built? Maybe for other projects or expanding the business, which also increase jobs. And with the bridge, once it is built, you do not need the workers any more. They lose their jobs. However, if you use the money to expand the business, people fill those new jobs, and these jobs stay, so the people stay.