From the Financial Times:
"After nine months' gestation, the Brexit process has started. On the negotiations, Oxford Economics suggests it can be boiled down to two pairs of issues. First, can the UK negotiate an ongoing trading relationship with the rest of the EU in time for the end of the Article 50 process in the two years' time, or will it be necessary to thrash out an intermediate agreement to tide things over? Second, which of two broad outcomes is more likely after that - a free-trade agreement (which could cover a multitude of sins) or a failed negotiation that leaves the UK and the EU trading with each other on the minimal terms mandated by the World Trade Organisation?"