3.4: Von Thünen’s Model

Figure 3-16: An adaptation of Von Thünen’s Model that predicts and/or suggests ideal locations for agricultural production based on distance to market and cost of transportation.

Weather, climate, and soils are important variables affecting the decision-making process of farmers, but the cost of transporting agricultural products is just as important. Two hundred years ago, economic geographer Johann Heinrich von Thünen recognized that because each crop presented a different set of transportation costs and challenges, profitable farming was partly dependent on distance to markets. His ideas led him to develop a theory of agricultural land rent that is now widely known as the Von Thünen Model.

This model incorporates several assumptions that are not always present in the real world, but the model is useful for understanding the decision-making process of agriculturalists. First, the model assumes that all farmland is of equal quality (topography, soil, water, etc.) and that no place has a transport advantage over any other (a river or rail line). Second, the model assumes there is only one market city where farmers sell their goods. Third, the model assumes farmers are economically rational: they understand how to maximize profit and always choose the most profitable use for their land.

Von Thünen argued that farmers living closest to the market city will produce dairy and/or fruits and vegetables because those products are both perishable and expensive to transport. Dairy farmers who live closest to urban markets will specialize in liquid milk, while dairy operations further from large cities will convert milk to less perishable dairy items like, butter, cheese, and ice cream because those products are less perishable. It would be foolish, especially in 1826, for farmers living at a great distance to the city to specialize in foods that spoil quickly. Von Thünen argued that farmers living far from the city market specialize in grain crops because they are cheaply transported and can be stored for long periods. Tree crops, used for home heating in the 1800s will be grown near the city because firewood was heavy and expensive to transport.

Figure 3-18: Oxnard, CA. A sign protesting the conversion of prime farmland on the Oxnard Plain into suburban housing tracts. Consider the difficulty of creating laws to prevent farm loss.

Figure 3-17: Union Stockyards, Chicago, IL 1947- livestock is prepared for slaughter near meat packing plants. Advances in transportation and refrigeration forced urban feedlots out of business by the mid-1900s. Source: Library of Congress.

Von Thünen knew that farmland near cities was more valuable because that land was also valuable for those interested in building housing, factories, etc. If farmers living near cities wanted to maximize the value of their land by farming, they had to engage in intensive agriculture, like fruit and vegetable farming known as market gardening. Otherwise, they should simply convert their farmland to some other purpose to make maximize their land rent. Farmers living further from cities, because they have greater costs associated with transporting crops to market, must engage in extensive agriculture, the type of farming best suited for less valuable land, which requires less costly farm labor.

Figure 3-19 : The refrigerated rail car radically changed the way distance factored into the operation of the Von Thünen Model. Can you think of affected farm commodities? Source: Wikimedia

Technological innovations, particularly refrigeration and rapid transportation undermine some of the applicability of Von Thünen’s model today, but the logic behind it is still very potent, and current agricultural maps reflect the ongoing importance of transportation costs to farmers. New York City, Los Angeles, and Chicago all have large hinterlands where farmers remain engaged in intensive market gardening and liquid milk production. New Jersey is called the “Garden State” for exactly this reason.

Figure 3-21: Los Angeles, CA - Cattle Cars like this one in a museum were rendered obsolete by the invention of refrigerated box cars, which in turn allowed urban stock yards also obsolete.

Market gardening farms still tend to be found in the US within a one-day drive to a nearby city’s central produce warehouse district. California, with the largest population of any state, therefore, leads the country in the production of fruits, vegetables, and milk – just as Von Thünen’s model would suggest. It’s not just the weather. Large grain farms continue to be rare in those same areas. The biggest changes from Von Thünen’s original model are the location of forestry operations and livestock feedlots. Thankfully, most hogs and cattle are fattened and slaughtered far from cities nowadays. Thanks to the elimination of wood as a heating fuel, fuel forestry regions, which once supplied wood to heat homes in the nearby city no longer exist.

CORN, SUGAR, FARM POLICY AND PUBL IC HEALTH

Today, the operation of Von Thünen’s Model is also affected by numerous government policies that greatly influence what farmers do and what we eat. To provide you some insight into how geography is useful in analyzing complex questions, the section below offers a quick case study into some of the relationships between politics, farming, dietary practices, and public health.

Figure 3-22b: Infographic - Since 1970 cheaply produced HFCS has replaced cane sugar, driving a significant increase in total sugar consumption in the US. Source: Wikimedia

Perhaps the most important food in the world is maize, popularly known as “corn” in the US. Domesticated by the indigenous people of Mexico thousands of years ago, maize has proven an exceptionally versatile and hardy plant. It’s so adaptable, that much of the world eats maize in some fashion today. There are multiple varieties of maize. Most Americans know maize as sweet corn or corn on the cob Sweet corn is also available canned and frozen and appears in a wide variety of dishes. Less well known are the dozens of maize varieties known as field corn, even though vastly more field corn is grown than sweet corn. Field corn is processed into dozens of other products. Some of it is ground into cornmeal and cornstarch, which we use to make things like corn chips, tortillas, and sauces. We also convert millions of tons of field corn into corn syrup and high fructose corn syrup (HFCS). Corn syrups are used as sweeteners, thickeners, and to keep foods moist or fresh. Since the early 1970s, HFCS has become a common and inexpensive replacement for cane sugar and beet sugar. HFCS is now the most common sweetener used in processed foods and soft drinks.

Figure 3-21: Sweet Corn. This variety of maize is consumed directly by humans, unlike field corn which is generally processed into flours, syrups or used for animal feed or fuel. Source: Wikimedia

Figure 3-21 Croatia. Field corn is the most common crop in the US, and ranks only behind wheat and rice worldwide. Source: Wikimedia

Cost is the main reason the displacement of granulated cane and beet sugars by HFCS in the American diet and the geography of sugar production explains the difference in costs. Field corn grows well in much of the US, so lots of it can be produced, which drives supply up and costs down. Sugar cane, on the other hand, is poorly adapted to most American climates. Sugar cane yields are highly dependent on climate. A good crop of sugar cane requires plenty of rain and a very long growing season, In the US, only Hawaii has ideal conditions for profitable sugar cane production. Cane yields in Hawaii are triple those in Louisiana, but delivery costs from Hawaii and competition for prime farmland on the islands drive up the price of Hawaiian sugar. Sugar beets grow well in a variety of climates. You might drive past a field of sugar beets in the desert of California and up in Minnesota. Half of the US granulated sugar production is made from sugar beets. Climate conditions and cheaper labor outside the US make foreign-produced sugar cheaper than domestic sources.

Figure 3-23: Brawley, CA. This massive sugar beet factory relies upon irrigation waters and helps promote the local dairy industry via by products. Note the sea-level marker.

Since the Great Depression of the 1930s, the US government has provided special subsidies to cane sugar producers to help keep them in business via tax breaks and a variety of other incentives. The government even buys cane sugar at prices above world market value if American sugar producers cannot profitably sell it on the international market. The US government also restricts sugar imports, especially from Cuba, which supplies sugar cheaply to Mexico and Canada. Tariffs on imported sugar also increase prices within the US.

These trade protection policies help sugar farmers stay in business, but they create burdens elsewhere in the economy that often hidden. Those hidden costs are known as externalities or external costs. Geographers tend to be very interested in identifying and calculating external costs because our discipline approaches most topics holistically. Geographers think it is important to calculate all costs and benefits of government programs including those that subsidize sugar production. Geographers keep a keen eye on hidden environmental and societal costs often overlooked by economists and accountants.

Figure 3-24: US Sugar Production Corn sweeteners are produced in the Midwest. Sugar Beets (green) are produced in California and elsewhere. Sugar cane is grown in Louisiana, Florida, Hawaii and Texas. Source: US Sugar Alliance

In addition to costing taxpayers billions of dollars, sugar subsidies and tariffs act to make cane sugar more expensive at the grocery store than it would be otherwise. Candy and soda manufacturers also pay higher prices for sugar because of these policies. As a result, many thousands of manufacturing jobs involving sugar (i.e., candy making) have left the US for foreign countries where sugar is cheaper. For example, in Mexico, where the industry is not subsidized or protected by tariffs, cane sugar costs about half of what it does in the US, so numerous candy factories have moved there. Brach’s Confections and Kraft Foods have both moved candy manufacturing plants out of the US in recent years because of the high costs of cane sugar. Many of you have probably drunk a so-called Mexican Coke: a Coca-Cola produced in Mexico. Many cola aficionados prefer these because in Mexico Cokes are still made with cane sugar, rather than the cheaper HFCS used to make Coke at most US bottling plants.

Figure 3-25: Coca Cola bottles from Mexico. Soft drinks produced outside the US are more likely to contain cane sugar because those manufacturers outside the US may buy cheap cane sugar from Cuba and elsewhere. Flickr

While the US government drives up the price of granulated sugar, US farm policy simultaneously drives down the price of corn and products made from corn. In 2014, there were about 1.63 billion bushels of corn left unsold at harvest. So abundant and cheap is field corn, that Americans are wasteful with it. About half of the yearly US crop of field corn is used (along with excess sugar cane bought by the government) to make biofuels, particularly ethanol fuel that is blended with gasoline. Much of the additional corn crop (both grain and silage) is used to feed cattle. Rather than feeding cattle grass and/or hay, which is their natural diet, we feed them corn because it is cheaper and fattens animals quickly. Chickens and hogs are also fed corn. The government even tries to get rid of corn by manipulating the definition of what counts as “healthy” in school lunches. In 2011, the US Congress famously declared pizza sauce a “vegetable”, over the objections of health advocates in an effort to help specific agribusiness interests.

Figure 3-26 US Map - Each point on this map represents 2,000 acres of corn grown for silage. Why might so many dots appear in Wisconsin? Source: USDA

Government policies make corn-based products cheaper than they would be in a free-market environment. Farmers growing fruits and vegetables are subsidized so those products are relatively more expensive. The differential government subsidies help explain why it’s a lot cheaper to buy a burger combo than a green salad in most places.

Figure 3-27: Northridge, CA - An advertisement for a burger combo meal at a campus fast food restaurant. A salad at a nearby restaurant on campus cost double on the day this photo was taken.

Poor people, whose health is often at risk from a variety of other factors, often become over-dependent on a diet of cheap, but fatty (corn-fed) meats, sugary processed foods, and starchy carbohydrates. Some scientists suspect that corn sweeteners play an additional role in the worldwide obesity crisis. They argue that although corn sugars taste similar to traditional sugars, HFCS alter human metabolisms, pointing to the fact that in the years since HFCS replaced cane sugar as the most common sweetener, a variety of obesity-related health issues have appeared in the US and elsewhere. Of course, the corn industry disputes these charges. Even if HFCS is not worse for you than granulated sugars, it is commonly accepted that diets high in fats and carbohydrates and low in vegetables invite a variety of chronic health issues, which in turn costs taxpayers even more via government-subsidized health care for the poor – yet another external cost perhaps overlooked by others.

Figure 3-28: US Map - The number of fast food restaurants and the rate of adult obesity are depicted simultaneously on this map. What criticisms of this map would you provide? Source: Wikimedia.