The incentives for writers and commissioners are totally different. In the American studio model, a one-season run is a failure. The process starts with the exp

The incentives for writers and commissioners are totally different. In the American studio model, a one-season run is a failure. The process starts with the expectation that successful shows run for dozens or hundreds of episodes. In the British model, you can try out a lot of ideas that just aren't possible in that framework. You can have more meaningful character and plot development, because you're not worried about dragging things out. The American sitcom trope of everything resetting to normal at the end of an episode just isn't necessary. Nobody at the network is going to tell you that you can't write out a major character half way through the first series. You can write tight, self-contained dramas that resolve within the course of a series without any cliffhangers. You can experiment with ideas that have merit, but don't have any obvious potential to sustain a long-running series.