Obviously Black Swan Green is a coherent, put-together novel, but I think there is something to the fact that many of these chapters can stand alone. They all have their own titles, which isn't necessarily an indication of their ability to be individual pieces of work, but it does hint at it. Each of the chapters also each has its own plot line and coherent enough endings to be written as short stories. For example, "knife grinder" can be seen as setting up a lesson for Jason within the chapter itself: he is approached by the knife grinder at the beginning of the novel asking to sharpen his knives and has little idea that this person is a Gypsy. He goes with his father to the VCC meeting looking to get rid of the Gypsies, and is still very ignorant of Gypsy lifestyle. Then, after hanging out with Dean's family and learning that Dean's father is part Gypsy, Jason seems to reconsider the fact that not all Gypsies may be dirty or "money grubbers" like his father seems to think. By the end of the chapter, after talking to a group of Gypsies and seeing how they actually live, Jason has changed his opinion on them and issues some very profound sentiments on how British people see themselves in relation to Gypsies. From this, we can see that "knife grinder" sets up a very clear story arc, and by the end Jason has learned an important lesson.
However, I am going to argue a bit with myself on this point. David Mitchell has strung these chapters together for a reason and obviously they will tell a storyline that spans the entire novel. Each chapter is set up very carefully with little facts dropped in each chapter that appear later in the book. In the interest of keeping the examples coherent, I'll again use "knife grinder" as an example. In this chapter we see the emergence of a character named Alan Wall, a kid Jason used to go to school with who crops up in the quarry. In "goose fair", the next chapter, we see him again now defending Jason when bullies come to pick on Dean and him. We also recognize Alan Wall's uncle, who is also a Gypsy, appear in this chapter. The recurrence of minor characters is clearly characteristic of a continuous storyline.
After presenting both arguments, I will say that I believe it is both. Obviously each of these chapters is taken from Jason's life so there must be some continuity to it, but I believe they can also be stand-alone. Strengthening this claim is the fact that we've seen that many of these chapters turn into individual poems that Jason has written.
