英国脱欧与非关税壁垒：对英国商业投资和生产力的影响

Ahmet Kara1Hailey LowStephenMillard1 1National Institute of Economic and Social Research About the National Institute of Economic and Social Research The National Institute of Economic and Social Research is Britain's longest establishedindependent research institute, founded in 1938. The vision of our founders was to carry outresearch to improve understanding of the economic and social forces that affect people’s lives,and the ways in which policy can bring about change. Over eighty years later, this remainscentral to NIESR’s ethos. We continue to apply our expertise in both quantitativeand qualitativemethods and our understanding of economic and social issues to current debates and toinfluence policy. The Institute is independent of all party-political interests. National Institute of Economic and Social Research2 Dean Trench StLondon SW1P 3HET: +44 (0)20 7222 7665E:enquiries@niesr.ac.ukwww.niesr.ac.ukRegistered charity no. 306083 This paper was first published inAugust2025 Competing Interest Statement: The views expressed in this paper are based on research andare not attributed to the organizations to which the researchers are affiliated. There are noconflicts of interest. The usual disclaimer applies. © National Institute of Economic and Social Research 2025 Brexit and Non-Tariff Barriers: Effects on UKBusiness Investment and Productivity Ahmet Kaya*,Hailey Lowand Stephen Millard1 Abstract This paper investigates the macroeconomic impacts of increased non-tariff trade costs resultingfrom Brexit onUKbusiness investment and productivity growth. We develop a three-countryDynamic Stochastic General Equilibrium model that accounts for differences in country sizes aswell as tariff and non-tariff trade costs. Our resultssuggestthat the increased trade costsresulting from Brexitledtoa sharp decline in trade between the United Kingdom and theEuropean Union, with imports decreasing by 23.7per cent and exports by18.6 per cent.Following an initial decline of around2.5per cent, business investment gradually recovers butultimately remains1.2per cent lower in the long term. We further provide simulations of thesame shock using the National Institute GlobalEconometric Model, NiGEM, whichsuggestscomparablemacroeconomic effects.The long-term impact on per capitaoutputis estimated at1.2per cent in our model, attributed solely to the rise in non-tariff trade barriers. Keywords:Brexit, business investment,non-tariff barriers, productivityJEL Codes: C50, C68, E37, F41 Contents Abstract...................................................................................................................................................................11. Introduction......................................................................................................................................................32. Literature Review............................................................................................................................................53. Model...................................................................................................................................................................83.1. Households...............................................................................................................................................83.2. Firms.........................................................................................................................................................103.3. Government...........................................................................................................................................113.4. Market Clearing....................................................................................................................................113.5. Calibration..............................................................................................................................................114. Impact of Brexit............................................................................................................................................144.1. DSGE Model Results...........................................................................................................................144.2. NiGEM Trade Scenarios.....................................................................................................................165. Conclusion......................................................................................................................................................20References..........................................................................................................................................................21Appendix..............................................................................................................................................................25 1.Introduction The United Kingdom has experienced a prolonge