Additional Math Pages & Resources

Thursday, September 1, 2011

Waste Not, Want Not, Part I

The premise of this blog is that elementary math can be used for a variety of things in adult life. I report on interesting ways that people understand the world around them, using math and numbers in the process.

Here's today's question - How can we use math to calculate the value and benefit of something that is free? Bear with me while I provide some basic history and explain what I mean:

Hunting/gathering differs fundamentally from today's agricultural and industrial economies. It means a society who practices direct procurement of edible plants and animals from the wild, and foraging and hunting without domesticating or using animals.

People move into an area, set up a temporary camp, and hunt or trap rabbits, birds, fish and so on, while also collecting berries, seeds, grasses, etc. When the area's output declines, the tribe moves on to a new area. This way of life was practiced in San Diego by the Kumeyaay people until the Spanish arrived about 240 years ago. Hunter/gatherers looked in every nooks and cranny for things to eat, and rarely had a surplus - this is subsistence living. Read more here.

Agriculture means cultivating plants and animals deliberately, or planting on specific plots of land with irrigation, fertilization, breeding, etc. It makes many things possible: stationary homes, surpluses, wealth, waste, and charity. Wikipedia suggests that one-third of the world's population is now engaged in agriculture, while producing only about five percent of the total economic value of world production.

The term gleaning means picking up food (and other things) after an agricultural harvest. In the Old Testament, Ruth searched for food in fields owned by Boaz, after the harvesters had passed through. A wealthy farmer, Boaz admired and eventually married Ruth. Their son Obed was grandfather of King David.

Gleaning appears about 20 times in the Bible. Some rabbis taught that fields should be under-harvested - a few good things should be left for the poor and for aliens and strangers. Other teachers insisted gleaning be reserved for widows and orphans. Based on Biblical precedent, gleaning was common practice in rural Europe during the Middle Ages.

A car full of gathered bread

Modern Gathering
Modern gathering practiced in the US is different from gleaning. A group of gatherers normally obtains permission to collect (scavenge) surplus materials, damaged crops, etc. Workers may take of a small fraction of what they collect, and the rest is distributed to others who are not able to do the gathering themselves due to age, illness, transportation, etc.

You can read about the AgAgainstHunger organization here. They are able to collect much of the 20% of harvest that goes to waste in California's Central Coast - over 1 million pounds a month.

A woman sorts food she has gathered for the hungry in San Diego

An odd-sounding English term called Usufruct came to describe these gleaning rights. English usufruct comes from a Latin expression usus et fructus, meaning "use and fruits". The poor can use or benefit from another person's property as long as they did not destroy or damage the property itself. The term fruits can mean any replenishable commodity on the property, including actual fruit, production of eggs or milk from livestock and even rental payments.

In an "amateur" context, we walk along the sidewalks and alleys and through canyons, gathering ripe citrus, figs, blackberries and other fruit that would otherwise be Fallen Fruit.

Why did I think of this subject for the blog? Yesterday I received a thank-you card from some friends who enjoyed a meal with us, featuring some gathered food. Their encouraging note ended with the admonition:

Usufruct With Impunity!