The truth, the whole truth, and nothing but the truth: the English Corn Returns as a data source in economic history, 1770-1914

From 1770 to 1914, the British Government collected weekly price and quantity data for all types of grain traded in many market towns; these Corn Returns were published in the London Gazette. We computerized the data published between 1770 and 1864, totalling around 6 million data points. Here we describe the nature of these data; discuss why, when, and how they were collected; consider their accuracy and biases; describe how we computerized them; and offer caveats in using theseuand similarudata. We highlight the problem of drawing valid inferences in the face of price impact from fluctuating grain quality and rising imports.