30 November 2018 L. Alan Winters CB, Professor of Economics and Director of the UK Trade Policy Observatory, Dr Michael Gasiorek, a Senior Lecturer in Economics at the University of Sussex and Peter Holmes, Reader in Economics at the University of Sussex both fellows of the UK Trade Policy Observatory. We welcome the Government’s estimates of the economic consequences of alternative Brexits. They are way overdue. The modelling was very competently done. But the assumptions made tended to favour the Government’s preferred position over other alternatives. On Tuesday, the UK Government released a set of cross-Departmental estimates of the possible economic costs of different Brexit options. They were based on the Government’s own modelling, which uses a technique known as a Computable General Equilibrium modelling and is based on the Global Trade Analysis Project (GTAP) consortium’s world model and dataset. The aim is to model (very approximately) the important linkages in an economy over a medium to long-term horizon and to assess the possible impact of changes in trade policy on the economy. (Short-term modelling, over a five year period, was simultaneously released by the Bank of England, but we do not discuss it here). The modelling approach is relatively [...]