Variations in the price and quality of English grain, 1750-1914:quantitative evidence and empirical implications.

Interpretation of historic grain price data may be hazardous owing to systematic grain quality variation – both cross sectionally and over varying time horizons (intra-year, inter-year, long run). We use the English wheat market, 1750-1914, as an example to quantify this issue. First, we show that bushel weight approximates grain quality. Then we show that cross sectional and intra-year variation are substantial and problematic, generating erroneous inference regarding market integration. Long run variation is significant, due to sharply declining international quality differentials, and this impacts estimated cost of living changes. By contrast, inter-year variation is smaller and controlled for more easily.