Forecasting UK inflation within the presence of enormous international shocks – Financial institution Underground

Dario Bonciani and Johannes Fischer

The UK economic system has been hit by important terms-of-trade shocks, most notably the rise in power costs following the Russian invasion of Ukraine. These shocks have created substantial and chronic inflationary strain in lots of international locations. Such upheavals carry elevated uncertainty concerning the future, making macroeconomic forecasting tougher. On this publish, we assess the forecasting efficiency of a state-of-the-art empirical mannequin, of the kind generally employed in tutorial analysis and coverage establishments. This mannequin is just not used to provide the Financial Coverage Committee’s (MPC’s) forecast however has been used periodically throughout the Financial institution of England together with as a cross-check to the principle forecast. Particularly, we assess its efficiency in predicting UK inflation out of-sample at key dates across the begin of the battle in Ukraine. The mannequin performs properly in forecasting short-term inflation, nevertheless it struggles to totally seize inflation persistence over the long run.

Methodology

To conduct our forecasting evaluation, we’ve employed a Bayesian Vector Autoregressive (BVAR) mannequin. All these fashions have gained widespread recognition in academia and central banks for his or her flexibility and robust forecasting skills, as evidenced by research like Bańbura et al (2010) and Angelini et al (2019).

In essence, this empirical framework encompasses a sequence of linear equations designed to mannequin the interdependencies and dynamics of macroeconomic variables. Additional particulars on BVARs could be discovered right here. Our specification contains 20 variables. Amongst these, 15 are particular to the UK economic system, together with the buyer costs index (CPI), actual gross home product (GDP), the Financial institution Fee, and particular parts of CPI, reminiscent of power and meals. Moreover, we incorporate international variables within the mannequin, together with world actual GDP, international commerce, and world CPI. Our mannequin specification was utilized in a current speech by Catherine L Mann, an exterior member of the Financial institution of England’s MPC. In her speech, she highlights how together with durations of excessive inflation, reminiscent of 2022 Q1–2023 Q2, within the estimation pattern impacts the inflation forecasts of the BVAR.

The BVAR mannequin depends on historic regularities between the included variables to provide forecasts. To seize these historic regularities, we estimate the mannequin parameters utilizing quarterly information from 1992 to 2019. To provide our BVAR forecasts, we make the extra assumption that the power and meals CPI parts within the mannequin are anticipated to comply with precisely the identical path as implied by real-time market futures curves (which shall be influenced by monetary market individuals’ expectations about future costs). This assumption permits our mannequin to consider details about the newest occasions affecting meals and power costs. This assumption is critical as we wish the mannequin to have all the data out there at every time limit. Utilizing the estimated historic regularities together with real-time info on the futures curves for power and meals costs, we then generate out-of-sample inflation forecasts at varied closing dates. On this publish, we give attention to the forecasts implied by the mannequin earlier than and after the onset of the Ukrainian battle.

Empirical mannequin estimated on pre-pandemic information

Chart 1 presents three panels illustrating inflation forecasts based mostly on real-time information at two distinct time factors: 31 January 2022 and 30 April 2022. The purple strains signify the BVAR forecasts, whereas the dashed strains depict the evolution of precise inflation. For comparability, we additionally embody the median inflation forecast from the Market Members Survey outcomes as inexperienced dots. Lastly, the shaded areas denote the statistical uncertainty surrounding the BVAR forecasts.

Chart 1: Evaluating inflation forecasts at totally different closing dates

In January 2022, as the specter of the Russian invasion turned extra seemingly, the BVAR forecast (higher Chart 1 panel) projected inflation to peak at 8% in November 2022. As compared, skilled forecasters anticipated inflation to peak at 6%, 2 proportion factors decrease than the BVAR.

Two months after the start of the Russian invasion, in April 2022 (decrease Chart 1 panel), each the BVAR {and professional} forecasters had adjusted their forecasts upwards to replicate the rise in power costs. Within the quick time period (the primary two quarters), the BVAR mannequin carefully tracked realised inflation. Nevertheless, inflation proved extra persistent than the mannequin’s historic regularities and futures curves about meals and power costs may predict. The hole between the forecast of the BVAR and that {of professional} forecasters that existed in January disappeared nearly fully by the top of April. One potential rationalization for the preliminary distinction in forecasts (and its disappearance) might be that skilled forecasters had not thought-about the Russian invasion of Ukraine to be as seemingly as monetary market individuals had. Lastly, skilled forecasters additionally didn’t anticipate inflation remaining excessive for an prolonged interval.

General, the BVAR mannequin’s forecasts implied excessive charges of inflation earlier than the Russian invasion of Ukraine however missed realised inflation by a number of proportion factors. As soon as the Russian invasion had begun, the inflation peak of the BVAR forecast is near the eventual peak.

Together with post-pandemic info

Lastly, we examined whether or not the persistent charges of inflation seen over the previous two years could considerably have an effect on future BVAR forecasts, as argued within the above-mentioned speech by Catherine L Mann. To take action, we re-estimated the mannequin with information that features the run-up in inflation up till 30 April 2023, excluding the outlier information throughout the pandemic years (2020–21), as per the methodology in Cascaldi-Garcia (2022). The out-of-sample forecast with the information out there at this time limit barely elevated the inflation persistence. Curiously, over the total forecast horizon, the predictions from the BVAR mannequin {and professional} forecasters aligned very carefully.

Chart 2: Does post-pandemic information have an effect on the inflation forecast?

Conclusion

Returning to our preliminary query, to what extent a linear mannequin can predict inflation within the face of enormous terms-of-trade shocks. Previous to the battle in Ukraine the mannequin forecasted inflation considerably under its eventual realisation. This isn’t shocking as a result of the mannequin couldn’t have foreseen the extent of the power worth improve related to the battle. Following the beginning of the battle, when the power worth improve was realised, the BVAR mannequin carried out properly in forecasting inflation within the nearer time period regardless of its relative parsimony. Nevertheless, it struggled to totally seize the inflation’s persistence over the long run. Utilizing information realisations from 2020 onwards to estimate the BVAR parameters can probably assist higher seize the persistence of inflation sooner or later. Our evaluation suggests {that a} linear mannequin such because the BVAR can nonetheless show to be strong for forecasting even in a turbulent macroeconomic surroundings.

Dario Bonciani and Johannes Fischer each work within the Financial institution’s Financial Coverage Outlook Division.

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