The British rock band The Clash’s hit “Should I Stay or Should I Go?” is #228 on Rolling Stone’s list of greatest rock songs. It’s a short, simple song about the inability to decide whether to stay in a relationship or leave it behind. The questions are practical, not emotional. It’s a good metaphor for the Brexit question. To be sure, there are emotional issues tied to the Brexit decision, especially regarding immigration and what is widely considered an unacceptable loss of sovereignty to the European bureaucracy, often simply referred to as Brussels. These issues are hard to quantify, both in how they shape the political environment and how changes in that environment will ultimately impact policy.