"A Christmas Carol is an argument for political reform. Discuss." In what ways does A Christmas Carol argue for political reform and what three arguments could be used in an essay surrounding this prompt?

In A Christmas Carol, Dickens presents, in an especially concise way, the recurring theme expressed in his work overall that the economic and political processes of his time were flawed and unjust.
First, Scrooge is an emblem of the owner class of his time who has little regard for the condition of the working class or even the poor middle class such as his employee Bob Cratchit, as evidenced by his refusal to give anything to charity and the scanty wages he pays Cratchit. Second, Scrooge, in spite of being a respected member of the London establishment, is completely without any religious feeling when the story opens, given his constant railing against Christmas as an occasion for togetherness or for people simply to show kindness to one another. Third, the visitation by Scrooge from the Ghost of Christmas Present shows a stark picture of the London slums, or at least the relatively poor neighborhood where Bob and his family live. One has to remember that Cratchit, in spite of his mistreatment by Scrooge, is a clerk in an office and therefore is probably better off economically than the actual working class of the 19th century, who were daily exposed to dangerous conditions in the early industrial facilities of the time and who, a half-century or more before workers began to unionize, were severely underpaid and had none of the rights that workers in Europe and North America enjoy today.
All of the above would suggest that Dickens is arguing for a change from the laissez-faire capitalism of his time to something akin to socialism, if not a complete overthrow of the system of ownership as Marx and Engels were advocating in the Communist Manifesto written about the same time. Yet, as George Orwell states in his essay on Dickens written in 1939, nowhere does Dickens in any of his books explicitly advocate socialism. Dickens reflexively sides with the underdog, the poor, and people who are mistreated. But he seems to be in favor more of a moral change in the system than a political one.
Scrooge is reborn in the course of the story. While it's unrealistic that even being visited by three ghosts would cause a permanent transformation in someone as cold as Scrooge, Dickens's whole "message" is that people can grow and change, and if there is a solution to the political and economic problems of the time, it's the responsibility of each person to bring this about through individual effort. In Great Expectations Pip goes through a similar process, though more gradual and less spectacular. When Pip comes into wealth he becomes a snob, looking down on Joe Gargery and his humble background. Later he is stunned and repelled by the revelation than Magwich is his benefactor, and learns a lesson similar to the one imparted to Scrooge.
In both cases, the change in the "system," whether political or economic, that Dickens advocates is not a radical transformation of society and ownership but a change in the way people think and act. In effect, he says, if people are kinder to each other, the world will become a better place.