Box sets » Uncertainty
Latest data from the ONS suggest that net migration to the UK was higher than previously thought in recent years, while it's also projected to be higher than previously expected. In this box, we presented our migration forecast and its impact on labour supply. As there is considerable uncertainty around the outlook, we also considered alternative scenarios for net migration and its economic impact.
The tax gap is the difference between taxes collected by HMRC and the theoretical liability, or what, in theory, should be collected. As a share of GDP, it has reduced from 2.3 per cent in 2005-06 to 1.5 per cent in 2021-22, two-thirds of which is explained by reductions in the VAT gap. In this box, we explored the recent drivers of changes in tax gaps, explained what assumptions we make about tax gaps in our forecast and outlined the associated uncertainties.
Debt interest spending has reached post-war records as a per cent of revenue and GDP in recent years and has also proved to be incredibly volatile and subject to large revisions between our forecasts. In this box we looked at the reasons for this elevated spending and volatility and how the process of quantitative tightening by the Bank of England will impact the maturity of this debt.
Inflation risks intensified after we closed our pre-measures forecast for the October 2021 Budget. This box showed two stylised scenarios embodying higher and more persistent inflation than in our central forecast to highlight the uncertainty surrounding the outlook. In one scenario inflation was driven mainly by pressures in the product market, and the other mainly pressures in the labour market, which had different implications for wages and consumption.
We illustrate the uncertainty around our forecasts using a variety of approaches. This box described using stochastic simulations to produce fan charts, which could be used to enhance presentation of uncertainty in future EFOs, and showed some experimental results.