What is the Law of Supply & Demand

For those that do not know what the law of supply and demand is, it is simply the relationship involving the suppliers and consumers of a given resource. The law of supply and demand describes the relation between a particular product and customer’s desire to purchase or sell said item. People are often inclined to provide more than they actually demand when prices rise and the opposite when prices drop. The basis of the law of supply & demand is centered on two discrete laws, these are the law of demand, and supply accordingly. Said laws work in tandem in order to determine an accurate market value and the amount of goods in circulation within the market.

Understanding the Law of Supply & Demand

Given that it is the one of the most rudimentary financial laws, said law of supply & demand is intertwined with practically all economic concepts in some way. Principally, the market equilibrium price is determined by people’s tendency to both supply and demand certain products, and or the cost at which the supply of an item that individuals are interested in offering matches the demand curve. Nonetheless, a variety of factors might influence supply or demand, making either rise or fall in a number of different ways.


According to the rule of demand, assuming all other conditions stay constant, the greater a products price, the less consumer’s desire said product. Essentially, as the price rises, so does the amount requested. Customers buy less of a product at a greater price since when a price of a certain product rises, so will the potential cost of purchasing said product. In consequence, people will refrain from purchasing certain products which requires individuals to push themselves to exclude something they hold higher in value in their lives.


The law of supply, similar to the law of demand, indicates that the amounts retailed for a given price. In contrast to demand, the law of supply relationship has a positive slope. Basically, this indicates that even as the price rises, so would the amount provided. From that of the seller’s viewpoint, the potential cost of every extra unit increases. Manufacturing those at a premium price offsets the greater economic price for every extra item sold.

One should know that it is crucial that both supply & demand recognize time as it is often an important component when it comes to graphically plotting them. For instance, when concerning the x-axis, the amount both demanded and supplied is consistently weighted in terms of a given product during a particular span of time. The forms both supply & demand curves can be influenced by longer or shorter time intervals.

Supply & Demand Curves

Supply for an item in a market remains fixed at any specific moment in time. Fundamentally, a supply curve is considered to be a vertical moving line, whereas the demand curve shows a constantly trending downward in accordance with a law of decreasing marginal value.

Note that that sellers could only charge what the current market allows depending on customer desire at the moment. Basically, as time goes by providers will and can adjust the amount of product said provider supply’s to consumers solely based on the desired price they want to charge for said product. This results in an upward slope for a supply curve of said product. Essentially, as prices that providers plan to charge for rise, the more likely that one is eager to generate said product and bring it into the market. Given that there are rules like the “rule of declining marginal utility”, across all periods of time, demand curves often trend in a downward manner.

One should note that during a transaction between a buyer and seller, the first product a buyer is likely to request would always end up as said buyer’s most purposeful item. In turn, any extra items purchased by the customer that are intended for use will be valued as a lower purpose item.

Shift vs. Movement

In economics movements or shifts can suggest various market happenings, albeit this is just in reference to both supply & demand curves.

The term “movements” simply refers to changes on a supply or demand curve. For demand curves, movements implies a that there has been an adjustment in the price & amount demanded of a given item from a point on our curve to another. Furthermore, movements imply that the relationship for the demand is continuous. Meaning that, any movements on that take place on along the demand curve only transpire when and if the price of the products fluctuate, as well as when the amount demanded differs in accordance with the starting demand connection. In simpler terms, movements only transpire when a shift in quantities that is requested is triggered solely when the overall price fluctuates.

Similar to movements in reference to demand curves, movements on a supply curve similarly indicate that just like demand curves, a supply curves relationship is continuous. Meaning that, any movements on the supply curve also and only transpire when the price of the products fluctuate, as well as when the amount demanded differs in accordance with the starting supply connection. Overall, movements only transpire when a shift in the quantity of products supplied is triggered solely by a change in the overall price.


Contrary to movements, when it comes to supply & demand curves shifts only transpire when the amount of product needed and product provided fluctuates despite the price remaining identical. To get a better understanding of when & how shifts occur let’s say the price of a pair of jeans is $40 and all off a sudden the amount of demand for jeans increases from the first quarter to second quarter of the year, this is referred to as a shift in demand for jeans. Similar to movements, shifts in a demand curve indicate that the initial demand “relationship” has been altered. This further implies that the amount of demand is subsequently influenced by aspects that do not include price. For example, if we think about the jeans from the previous example, a conceivable way that a shift in a demand relationship regarding jeans could transpire would be if jeans all of a sudden became the only form on pants available to the public.

Supply works in the same way as demand, for instance, when it comes to our aforementioned jeans, let’s say the price of jeans is $40 and suddenly the amount of jeans supplied to the public declined from the first quarter to second quarter of the year, this is referred to as a shift in supply for jeans. Similar to shifts for demand curves, shifts in supply curves imply that the initial demand “relationship” has been altered. This further implies that the amount of supply is subsequently influenced by aspects that do not include price. For example, if we think about the jeans from the previous example, a conceivable way that a shift in the supply curve for jeans could transpire, would be if some mass shortage of cotton. This would mean that jeans producers would end up supplying less jeans at the same price as before.

Equilibrium Price

The equilibrium price, otherwise known as a market-clearing price, is defined as the price that a manufacturer can retail the products they want to make, so that the consumer can purchase any amount of the product(s) they want to acquire.

When a positive slope is present for a given supply curve and a subsequent negative slope is present for a demand curve, it can be seen that they will cross at some point. Let’s call this point P. At point P, it is evident that market price is adequate enough to persuade suppliers to provide the market with the same number of items that customers are ready to pay for at the currently listed price. In this instance, demand & supply are equal. When this equilibrium occurs is determined by the form and location of the demand & supply curves that are controlled by a variety of variables.

Factors Affecting Supply

Supply is heavily determined by manufacturing costs which include the following:

1. Materials & Labor, these represent the potential expenses for other ways to deliver different products to consumers
2. The technological equipment that can be used to integrate inputs.
3. A quantity of vendors and the total producing capability that they can have within a specified time period.
4. Tax, regulation, or other institutionalized production expenses

Factors Affecting Demand

The most fundamental predictor of demand is customer preference among various commodities. Although, there are other things can affect demand, for instance, consumer items that are alternatives or complementary products, as well as their costs. Another significant factor affecting demand is the change in variables that impact customer choices, for example, any and all seasonal variations or effects of advertising. Income fluctuations can also have an impact on the amount requested at any given price. Income fluctuations can also have an impact on the amount requested for any specified price.

What Is a Simple way to Describe the Law of Supply and Demand?

In more simple terms, the Law of Supply & Demand can be defined as a phenomena that we are all familiar with in our daily lives. Essentially, it is similar in the sense that it illustrates that when everything is equal, items become more rare if the price of an item rises and supply of said item declines in response, and or when the demand for said item rises also making it increasingly uncommon. In contrast, it illustrates why the price of an item will fall if they are more universally accessible or less desired with buyers. Fundamentally, this principle is essential in modern day economics.

What Is the Importance of the Law of Supply and Demand?

It can be stated that The Law of Supply and Demand is critical as it assists investors, businessmen, and economic experts in understanding and forecasting future market positions. For instance, a corporation releasing a new item may purposefully attempt to increase the price for the product by building customer needs via advertisement.

Although, other methods companies might employ to increase prices is by purposely limiting the amount of products sold in order to reduce supply. If this were to occur, supply would, in turn, be reduced but demand would continue to rise providing the company the higher price.

What Is an Example of the Law of Supply and Demand?

Consider the preceding scenario, in which firms advertise an innovative or new product in order to boost pricing. Said corporation will want to keep manufacturing extremely in order to maximize potential profit margins.