分析财政大臣的税收选择

Ed Cornforth NIESR Policy Paper 47October 2025 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 quantitative and qualitativemethods and our understanding of economic andsocial 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.ukniesr.ac.ukRegistered charity no. 306083 Policy papers are written by members of the National Institute of Economic and Social Research tospecifically address a public policy issue. These may be evidence submitted to a public orparliamentary enquiry,or policy research commissioned by a third-party organisation. In all circumstancesNIESRhasfull editorial control of these papers. We will make all policy papersavailable to the public whether they have been supported by specific funding as a matter of course.Some papers may be subsequently developed into research papers This paper was first published inOctober 2025.© National Institute of Economic and Social Research2025. Contents Introduction...............................................................................................................................................................4Analysis of Different Tax Options......................................................................................................................5Comparing the Main Three Options.............................................................................................................5Income Taxes in Detail.......................................................................................................................................8Conclusion...............................................................................................................................................................10Bibliography............................................................................................................................................................11Appendix 1: Simulation Assumptions.............................................................................................................12 Introduction In our recent forecasts,NIESR have highlighted theneed to raise revenue as part of the“Chancellor’s Trilemma”, with forecasts suggesting that the government is not on track to meetits ‘stability rule’, with a current projected deficit of £41.2 billion in the fiscal year 2029-30(NIESR, 2025).Given that it is likely that the OBR will forecast a current deficit in 2029-30–withcommentators suggesting numbers between £20 and £30 billion–ifthe Chancellor is to stick toher fiscal rules,and not doing so would likely provoke an adverse market reaction,then she willhave to cut spending or raise taxes.Given that the Comprehensive Spending Review was onlyconcluded recently, and attempts to reduce the welfare bill were met with opposition fromwithin her own party, reducing spending does notseem to be an option available to theChancellor either. So, it is very likely that she will have to raise taxes.This policy briefarguesthatthe most realistic option is to raise one of thefourmain taxes:corporation tax, income tax,employee National Insurance Contributions (NICs)orValueAddedTax (VAT).This being thecase, the rest of the brief explores theeffects on the economy of raisingthesetaxes, arguing thata rise in income tax is likely to have the leastnegative effect on GDP and so isthe best of theoptions available to the government. 11The governmentpledged in its manifesto that it ‘would not raise taxes on working people’and,since being in government, they have ‘doubled down’ on this pledge.This pledgehas now beeninterpreted to mean that they will not raiseVAT,employee NICsorincome tax.We would arguethattheycould find other ways to raise taxrevenuebutdoing sowould bemuch more distortive,harming the economy in the longer run.Raising employer’s NICs is a good example of this; NIESRhave previously found it to be very harmful to the economy, increasing inflation and interestrates, and reducing growth and employment(Cornforth, 2025). Wealth taxes have been proposed as a way to raise revenue. However,thiswould likely lead to areduction in savings that, in turn, wouldraisethe cost of capital, reducing investment in thefuture. Furthermore, unless it is designed in a completely watertight fashion, it risks leading todistortive behaviour as individuals change relative asset class holdings to avoid the tax; thi