Yield and price: how a UK harvest shock reaches the market
The economic logic
Wheat is fungible and traded globally. A poor UK harvest tightens the domestic balance sheet, less home-grown grain, more import pull, firmer regional premiums over the futures benchmark. So the sign of the relationship is exactly what theory predicts: lower yield, firmer price. What theory also predicts, and the numbers confirm, is that the magnitude is small relative to the global drivers stacked on top.
Year by year
Our national directional lean, the actual UK yield anomaly (versus trend), and how ex-farm feed wheat moved across that harvest's marketing year (post-harvest autumn → the following summer). Price data begins in 2015. The lean is shown only where it was strong enough to stand behind; the confidence-filtered, region-by-region accuracy that gives the 62.3% headline is on the track record.
| Marketing year | Our yield lean | UK yield anomaly | Ex-farm price move |
|---|---|---|---|
| 2015/16 | Near avg | +0.11 | +9.2% |
| 2016/17 | Near avg | +0.88 | +10.5% |
| 2017/18 | Near avg | +0.05 | +22.7% |
| 2018/19 | Near avg | +2.04 | -20.2% |
| 2019/20 | Below avg | -1.66 | +23.4% |
| 2020/21 | Near avg | -0.05 | +6.4% |
| 2022/23 | Near avg | +0.48 | -30.9% |
| 2023/24 | Below avg | -1.03 | -3.4% |
| 2024/25 | Near avg | -1.41 | -10.0% |
How tight is the link? Honestly: loose.
Across the 9 marketing years with price data, the correlation between the UK yield anomaly and the ex-farm price move over the year is r = -0.38 (p = 0.32, n = 9). The negative sign is the right direction, lower yield, firmer price, but it is weak and not statistically significant on this sample. Yield explains only a small share of the year-to-year price swing.
The clearest example of the limit: 2022/23. The UK harvest came in +0.48 versus trend (slightly above normal, which all else equal should soften price), yet ex-farm feed wheat moved -30.9% across that marketing year. That swing was the global market unwinding the 2022 invasion-spike, nothing to do with the size of the British harvest. When the world moves, UK yield is a rounding error on flat price.
Where a UK yield edge actually pays
Knowing the UK harvest before the trade reports do is valuable, just not as a flat-price punt:
- Basis & regional premium, a short domestic crop widens UK premiums over the futures benchmark; an early read on that is edge for a grain merchant.
- Reserving & claim timing, a below-average UK harvest is a leading indicator for a crop insurer's parametric and shortfall exposure.
- Directional overlay & risk timing, a UK supply-side surprise is one input a commodity desk can fold into a wider book, well ahead of official estimates.
Our skill is at the yield step
This page is about the downstream link from yield to price, which is loose. The thing CropIntel is actually good at is the step before it, calling the UK yield itself, with a walk-forward hit rate of 62.3% over 23 years. That record, region by region and year by year, is on the track record.
Related: Today's call · Track record · By the numbers · Methodology. Not financial advice, see the footer.