Because you must cede a small part of your sovereignty to be part of that market. Switzerland had done this through treaties with the EU. https://en.m.wikipedi

Because you must cede a small part of your sovereignty to be part of that market. Switzerland had done this through treaties with the EU. https://en.m.wikipedia.org/wiki/European_Single_Market https://en.m.wikipedia.org/wiki/European_Single_Market