Options trading
Stock & Commodity Trading


Law of Supply and Demand


In a market economy, price is determined by the interaction of supply and demand. In this section we will demonstrate how to estimate a market price for commodities using the law of supply and demand as reflected in the "stocks to use ratio". The stocks to use ratio is a closely watched figure in when establishing asking prices for commodities. In order to understand stocks to use, you must understand the economic theory of supply and demand.

Law of Demand

The law of demand and its application to fundamental analysis of commodities rests upon an understanding of consumer behavior. The factors, which characterize consumer choice, and how individual consumer responses are reflected in the market place, are key components of this economic theory. Understanding what factors have affected demand in the past will help to develop expectations about demand in the future and the impact on market price. Demand for a particular product or service represents how much people are willing to purchase at various prices. Thus, demand is a relationship between price and quantity, with all other factors remaining constant.

Generally the relationship between price and quantity is negative. This means that the higher is the price level the lower will be the quantity demanded and, conversely, the lower the price the higher will be the quantity demanded. Market demand is the sum of the demands of all individuals within the marketplace. Market demand will be affected by other variables in addition to price, such as various value added services including handling, packaging, location, quality control, and financing. Thus the demand for an agricultural commodity is typically derived from the demand for a finished product.

It is important for you to understand that a free market economy is driven not by producers but by consumers. Ultimately the market value for any good or service is determined by its value to the consumer. Higher prices mean higher profits and higher profits provide you with the incentive and the means to expand production of those goods and services that consumers value the most. So profit driven expansion is the marketís response to stronger buyer demand. On the other hand, when consumers are unwilling to buy what is offered at the current price, the seller will have to lower the price ultimately resulting in lower profits or losses to the producer. Losses reduce the producerís incentive to produce things that have weak demand, which will ultimately force production cuts as farmers lose more and more money.

This is the discipline of the marketplace. Those who produce things that consumers are willing and able to buy are rewarded. Those who produce things that consumers donít want or canít buy are penalized. Farmers must produce for the markets. They cannot expect to find or create a profitable market for whatever they choose to produce.

Law of Supply

Supply joins demand as one of the components of fundamental commodity market analysis. Supply characteristics relate to the behavior of firms in producing and selling a product or service. An understanding of the factors affecting supply in the past will help with the development of supply expectations in the future and the impact upon market price.

The law of supply can be approached from two different contexts. The first is that it represents the sum total of production plus carryover stocks. The other context for supply describes the behavior of producers. The market or total supply represents the quantities producers are willing to sell over a range of prices for any given time period. At the individual level, you may be willing to produce a given product as long as the market price is equal to or greater than the cost of producing that product. The total supply is the sum of the individual quantities of product that each farmer brings to the market.

An increase in price in most instances will result in farmers wanting to increase the quantity of a given product they will bring to the market, therefore the relationship between the price and supply is positive. Market supply will be affected by other variables in addition to the price. Factors that have been identified as important in determining supply behavior include; the number of firms producing the product, technology, the price of other commodities which could be produced, and the weather.

With higher prices the producers of goods and services will receive greater profits. Greater profits will result in the means to expand production increasing the supply. This increased supply will ultimately satisfy the existing demand such that any additional production must be met with new demand in order for the price increases to be sustained. The firms which handle grain or livestock products are not free to set prices as they choose. They can raise prices only if consumers are willing and able to pay more. The law of supply, as was the case with demand, illustrates the discipline of the marketplace. The market doesnít care what it costs you to produce something. Lower prices are the marketís signal to farmers that they have produced too much of something or that it is something consumers do not want.

How Supply and Demand determine Commodities Market Prices

 Price is derived by the interaction of supply and demand. The resultant market price is dependant upon both of these fundamental components of a market. An exchange of goods or services will occur whenever buyers and sellers can agree on a price. When an exchange occurs, the agreed upon price is called the "equilibrium price", or a "market clearing price".

A market price is not a fair price to all participants in the marketplace. It does not guarantee total satisfaction on the part of both buyer and seller or all buyers and all sellers. This will depend on their individual competitive positions within the market. Buyers will attempt to maximize their individual well being within certain competitive constraints. Too low a price will result in excess profits for the buyer attracting competition. Likewise sellers are also considered to be profit maximizers. Too high a price will likewise attract additional producer competition within the market. Therefore, there will exist different price levels where individual buyers and sellers are satisfied and the sum total will create a market or equilibrium price.

When either demand or supply changes, the equilibrium price will change. For example, good weather normally increases the supply of grains and oilseeds, with more products being made available over a range of prices. With no increase in the quantity of product demanded, there will be movement along the demand curve to a new equilibrium price in order to clear the excess supplies off the market. Consumers will buy more but only at a lower price.

Likewise a shift in demand due to changing consumer preferences will also influence the market price. In recent years there has been a shift in demand on the part of overseas Canadian wheat buyers toward the Canada Prairie Spring varieties, away from the Hard Red Spring varieties.

With no reduction in supply, the effect on price results from a movement along the supply curve to a lower equilibrium price where supply and demand is once again in balance. In order for prices to increase producers will have to reduce the quantity of hard red spring wheat brought to the market place or find new sources of demand to replace the consumers who withdrew from the marketplace due to changing preferences or a shift in demand.

Changes in supply and demand can be short run or long run in nature. Weather tends to influence market prices generally in the short run. Changes in consumer preferences can have either a short run or long run effect on prices depending upon the goods or services, for example whether they are luxuries or necessities. A luxury good may enjoy a short-term shift in demand due to changing styles or snob appeal while necessities tend to have stable or long run demand curves. Another major factor influencing market prices is technology. A major effect of technology in agriculture is to shift out the supply curve rapidly by reducing the costs of production on a per unit basis. At the same time if total demand does not increase sufficiently to absorb the excess goods produced at lower costs, the long run impact of technology on the market place will be to lower prices. The rapidly shifting supply curve coupled with a slower moving demand curve has generally contributed to lower prices for agricultural output when compared to prices for industrial products.

 Return to Commodity Option Training

Commodity Trading

Options Trading
© Copyright 2008 Commodity-Option-Training.com. All rights reserved. Futures Options