Compare two EFO vintages

Pulls the same EFO table from two vintages and returns a tidy diff with a revision column (value_b - value_a). Useful for quantifying how the OBR's view changed between fiscal events.

Usage

obr_compare_vintages(
  vintage_a,
  vintage_b,
  what = c("fiscal", "inflation", "labour", "output_gap"),
  refresh = FALSE
)

Arguments

vintage_a, vintage_b

EFO vintage labels (e.g. "October 2024", "March 2026"). Use obr_efo_vintages() to see all valid labels.

what

Which EFO table to compare. One of "fiscal" (Table 6.5 aggregates, the default), "inflation" (sheet 1.7), "labour" (sheet 1.6), or "output_gap" (sheet 1.14).

refresh

Logical. If TRUE, re-download even if cached files exist. Defaults to FALSE.

Value

An obr_tbl with the standard v0.4.0 schema columns (period, period_type, series, metric_type, unit) plus value_a, value_b, and revision (value_b - value_a). Provenance points at the second vintage; the first vintage URL is recorded in the notes field.

Details

Rows are the inner join of the two vintages on the schema keys (period, period_type, series, metric_type, unit). Periods or series that are present in only one vintage are silently dropped. If you need to see what was added or removed between vintages, compare obr_efo_vintages() row counts or call the underlying functions directly with each vintage and setdiff() on the keys.

Calling the function with vintage_a == vintage_b is allowed and returns an all-zero revision column. There is no special handling beyond that.

See also

Other forecasts: get_forecast_revisions(), get_forecasts(), list_forecast_series(), obr_actual_vs_forecast(), obr_forecast_panel()

Examples

# \donttest{
op <- options(obr.cache_dir = tempdir())
diff <- obr_compare_vintages("October 2024", "March 2026")
#> ℹ Loading from cache. Use `refresh = TRUE` to re-download.
#> ℹ Downloading efo_aggregates_march_2026.xlsx from OBR...
#> Waiting 2s for retry backoff ■■■■■■■■■■■■■■■                 
#> Waiting 2s for retry backoff ■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■  
#> ✔ Saved to cache.
diff[diff$series == "Net borrowing", ]
#> # obr_tbl: 5 rows x 8 cols
#> # Source:       OBR Economic and Fiscal Outlook, March 2026
#> # URL:          https://obr.uk/download/march-2026-economic-and-fiscal-outlook-detailed-forecast-tables-aggregates/
#> # Retrieved:    2026-05-07 21:09:12 UTC
#> # File MD5:     43d7526594ab
#> # Package:      obr 0.5.0
#> # Note:         Vintage diff: October 2024 (a) -> March 2026 (b). revision = value_b - value_a. Earlier vintage URL: https://obr.uk/download/october-2024-economic-and-fiscal-outlook-detailed-forecast-tables-aggregates/
#> 
#>     period period_type        series metric_type   unit   value_a   value_b
#> 6  2025-26 fiscal_year Net borrowing       level gbp_bn 105.57651 132.73508
#> 13 2026-27 fiscal_year Net borrowing       level gbp_bn  88.45967 115.46142
#> 20 2027-28 fiscal_year Net borrowing       level gbp_bn  72.16790  96.46737
#> 27 2028-29 fiscal_year Net borrowing       level gbp_bn  71.90672  86.01563
#> 34 2029-30 fiscal_year Net borrowing       level gbp_bn  70.58379  63.40344
#>     revision
#> 6  27.158562
#> 13 27.001754
#> 20 24.299469
#> 27 14.108919
#> 34 -7.180343

# Compare the inflation forecast across two vintages
inf_diff <- obr_compare_vintages("October 2024", "March 2026",
                                 what = "inflation")
#> ℹ Loading from cache. Use `refresh = TRUE` to re-download.
#> ℹ Loading from cache. Use `refresh = TRUE` to re-download.
options(op)
# }