# Bushels Are Commodity-Specific

I like obscure units a lot, but mostly they're historical curiosities. It doesn't matter that an [ounce](https://en.wikipedia.org/wiki/Ounce#International_troy_ounce) of gold is heavier than an [ounce](https://en.wikipedia.org/wiki/Ounce#International_avoirdupois_ounce) of feathers while a [pound](https://en.wikipedia.org/wiki/Pound_(mass)#Avoirdupois_pound) of feathers is heavier than a [pound](https://en.wikipedia.org/wiki/Pound_(mass)#Troy_pound) of gold, or that a [pint](https://en.wikipedia.org/wiki/Pint#US_dry_pint) of raspberries is bigger than a [pint](https://en.wikipedia.org/wiki/Pint#US_liquid_pint) of raspberry jam. But one place where this still comes up is the [bushel](https://en.wikipedia.org/wiki/Bushel).

Bushels are [traditionally](https://en.wikipedia.org/wiki/Winchester_measure) units of dry volume, and a bushel basket is about as big as one person can carry. Today they're still in common use as a standard unit for many commodities: if I look up the price of [corn](https://markets.businessinsider.com/commodities/corn-price), [oats](https://markets.businessinsider.com/commodities/oats-price), or [soybeans](https://markets.businessinsider.com/commodities/soybeans-price) I'll see prices quoted in $/bushel. But it's not just a unit of volume anymore, and hasn't been for over a century.

The problem is, volume is not conserved. If you build a railcar with a volume of 3,000 bushels you can dump more than 3,000 bushel baskets of corn into it because the bottom corn will get a bit squished. While farmers generally still work with volumetric bushels, when they sell their crops buyers pay based on weight. But they still call it bushels!

This goes back a long way: here's a table from [~1854](https://en.wikipedia.org/wiki/Bushel#/media/File:Bushel_Table_of_States.jpg) showing how everyone (except MO) agrees that a bushel of corn means 56lb, or everyone (except CT) agrees a bushel of wheat means 60lb:

[![](https://www.jefftk.com/bushel-table.jpg)](https://www.jefftk.com/bushel-table-big.jpg)

As you can see, these amounts varied by state, and still do. Here's [RI law](http://webserver.rilin.state.ri.us/Statutes/TITLE47/47-4/47-4-2.HTM):

> § 47-4-2. Weights of bushels, barrels, and tons of specific commodities.
> 
> The legal weights of certain commodities in the state of Rhode Island shall be as follows:
> 
> 1.  A bushel of apples shall weigh forty-eight pounds (48 lbs.).
> 2.  A bushel of apples, dried, shall weigh twenty-five pounds (25 lbs.).
> 3.  A bushel of apple seed shall weigh forty pounds (40 lbs.).
> 4.  A bushel of barley shall weigh forty-eight pounds (48 lbs.).
> 5.  A bushel of beans shall weigh sixty pounds (60 lbs.).
> 6.  *\[38 more bushel definitions\]*

And here's [IL law](https://casetext.com/regulation/illinois-administrative-code/title-8-agriculture-and-animals/part-600-weights-and-measures-act/subpart-g-advertisement-of-the-price-of-liquid-petroleum-products/table-b-standard-weight-per-bushel-for-agricultural-commodities):

> §152, Weights & Measures Act
> 
> 1.  Alfalfa Seed: 60 Pounds
> 2.  Apples, Green: 47 Pounds
> 3.  Apples, Dried: 24 Pounds
> 4.  Barley: 48 Pounds
> 5.  Beans, Green or String: 24 Pounds
> 6.  *\[56 more bushel definitions\]*

Of the first three matching ones (apples, dried apples, barley), only the barley definition is consistent.

In 1904 [NIST](https://en.wikipedia.org/wiki/National_Institute_of_Standards_and_Technology) published [Laws Concerning the Weights and Measures of the United States](https://www.google.com/books/edition/Laws_Concerning_the_Weights_and_Measures/u2znAAAAMAAJ?hl=en&gbpv=0%22) which included an attempt to collect every relevant state-level law, ending with a 4-page appendix summarizing the state-level per-commodity bushel definitions:

[![](https://www.jefftk.com/state-level-per-commodity-bushel-definitions.png)](https://www.jefftk.com/state-level-per-commodity-bushel-definitions-big.png)

I'm curious how this is handled with national-level markets: does everyone use IL bushel definitions because that's where the [CME](https://en.wikipedia.org/wiki/Chicago_Mercantile_Exchange) is based? Are there now USDA definitions and the state definitions are still on the books but don't do anything? There's so much nested complexity here and I love it.