New major updates to UKMOD, our tax benefit microsimulation model for UK and devolved nations

UKMOD is the tax-benefit microsimulation model developed at ISER at our Centre for Microsimulation and Policy Analysis led by Professor Matteo Richiardi. UKMOD permits analysis of the effects of taxes and social benefits on household incomes and work incentives for the population of each nation in the UK, as well as user-defined individual profiles. It is unique as it features great flexibility in the scope of its simulations and ensures cross-country consistency of the modelling approach and comparability of the results with the EU models

UKMOD B1.08 has been released, with major updates including a new HBAI extension allowing to use HBAI data and weights, input data updated to 2021, and improvements to the modelling of Council Tax.

The new model includes:

Parameter Updates:

  • Completion of parameter updates for 2023/24 fiscal year

Data Revisions

  • Allowance for HBAI data and weights – see the new HBAI model extension
  • New “a” and “b” datasets now supported, based on data reported by the FRS 2021.
  • Model adapted to improve Council Tax levels where these are not explicitly reportedby the FRS. The FRS has made new information available for imputing Council Tax levels(ctamtbnd) from 2018/19. We have extended the model to make use of thesedata, which help to improve the match between UKMOD and officialreported measures of council tax (net of associated benefits) – see below for further detail.

Policy Reforms

  • Allowance for omission of means-test to Free School Meals implemented for London and Scotland
  • Bedroom tax adjusted to adapt treatment for disability benefit recipients
  • Eligibility condition for Best Start Foods extended

Code Corrections and Amendments

  • NRR and MTR add-ons adjusted to correct minor bugs improving consistency ofresults, and now append associated output to standard model output. Summary statistics from the NRR and MTR add-ons are now reported by model templates accessed via Statistics Presenter
  • Extension of model to support projection of indirect taxes
  • Minor code corrections to fix warning messages
  • Removed Parental Benefit switch
  • Revised part-year allowance for Health and Social Care Levy


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