Courses
Courses for Kids
Free study material
Offline Centres
More
Store Icon
Store

Shifts in Demand and Supply

Reviewed by:
ffImage
hightlight icon
highlight icon
highlight icon
share icon
copy icon
SearchIcon

The law of supply and demand represents the interaction between manufacturers and consumers. This theory shows how these two concepts are interlinked, and the price of a product can affect its sales. The supply-demand curve represents this concept in a graphical manner for better understanding.


Supply and demand law are one of the fundamentals of economics that is related to almost every principle of economics. Moreover, this supply-demand principle also affects the equilibrium prices of a product and often determines its price. However, there are various reasons that can affect this principle.


Shift in Supply Demand Curve

If there are any changes in this curve, it has a direct effect on market equilibrium. Here are some notable factors that can affect supply and demand –


1. Change of Demand

The demand for a product changes due to one of the following factors –

  • Population

  • Per capita income

  • Preferences

  • Value of the essential commodities

  • Value of substitute items

  • Forecast of change in prices

2. Change in Supply

Supply of an item alters owing to the following reasons –

  • Number of manufacturers

  • Taxes levied

  • Technological advancement

  • Aim of the companies

  • Cost of factors of production

  • Cost of competitive products

  • Expectation of future price change

This offers a brief idea about the major factors that have an effect on supply and demand. However, to understand this concept in detail, one must understand how a market reacts when both supply and demand curve shifts.


When Demand Changes

Increase in demand and decrease in demand plays a crucial role in determining the price of a product. Here is a detailed discussion regarding that –

  • Demand Increase

When supply remains constant, but the demand surges, it tends to shift the demand curve rightwards. If the demand for a product steadily rises, it ultimately affects the equilibrium price. Therefore, this price rise also increases competition among buyers, which also hikes the price of a product.


On the flip side, this rise in price serves as an incentive to the manufacturers. They will then increase production and supply that will result in falling demand. A point to note here is that this process stays operational until a new equilibrium is set. Resultantly, there is a hike in both the equilibrium price and quantity.

  • Demand Decrease

Similarly, if the supply remains constant, and demand for a product plummets, the demand curve will shift towards the left. In a situation like this, a condition of excess supply occurs at the equilibrium level. This situation leads to a competition between sellers, who want to sell their products due to this fall of prices.


Alternatively, once a product’s prices go down its market demand increases. This demand then leads to an increase in supply and manufacturing. This process then continues till a new equilibrium is in place. Resultantly, there is a reduction in the equilibrium price as well as quantity.


When Supply Changes

Supply-demand curve also observes a shift when there is any alteration in the supply of a product. Here are two phenomena regarding that –

  • Increase in Supply

When demand remains constant with a change in supply, it tilts the supply curve towards right. Therefore, when the supply of a product rises its demand at the equilibrium level also increases. This situation leads to a competition among sellers, which results in a drop in prices of a product.


Moreover, this lowering of prices also increases the demand for a product in the market, which also affects its production. This process continues till a new equilibrium is found, and at that point, the price of a product decreases and its quantity increases.

  • Decrease in Supply

Similarly, when the demand of a product remains constant, but its supply plunges, it shifts the supply curve towards left. This reduction of supply creates an excess demand at the equilibrium level, which results in an increase in the price.


Contrarily, this price hike will be accompanied by a lowering of demand and excess supply. This process will also carry on until a new equilibrium is found. Thus, the equilibrium price of a product will rise, but its quantity will fall.


Change of Both Supply and Demand

The market situation is more complicated than the above-mentioned increase and decrease in supply and demand. Usually, supply and demand do not alter individually; instead, they change simultaneously. Here are four such occasions that arise in the real world –

  1. Demand decreases and supply decreases

  2. Demand increase and supply increases

  3. Supply increase but demand decreases

  4. Supply decreases and demand increases

A supply-demand curve is a pictorial representation of this discussion. This chapter of modern economics is vital for individuals to learn as it can help them comprehend the basis of economics. On e-learning platforms like Vedantu, they can access relevant study materials of this chapter. Also, they can register for an online class and doubt clearing session to enhance their preparations further.

FAQs on Shifts in Demand and Supply

1. What Happens When Both Supply and Demand Plummets?

Ans. A drop in both demand and supply results in three factors. Firstly, if the drop is equal in both the fronts, the price of a product remains constant, but its quantity lowers. Secondly, when the fall of demand is higher than that of demand, it drops the price and quantity. Lastly, if the reduction in demand is smaller than supply, it gives rise to price, followed by a fall in quantity.

2. What Changes the Supply Curve?

Ans. Supply curve changes according to the demand of a product. In case the demand for a product is low, in that case, a supply curve will be likely to move towards the left. It means it will go down. On the contrary, products with high market demand witness and increase in supply curve. Any change to a supply curve is a direct effect of demand for a product and its market price.

3. What Happens When the Demand for a Product Increases, but its Supply Drops?

Ans. In such a case, the supply-demand curve moves in the opposite direction. Moreover, there are three cases to understand this concept further. At first, if the increase in demand is equal to its supply drop, it results in a price hike of that particular product. Secondly, if the increase in demand is greater than the decrease in supply, it hikes its price and quantity. Lastly, if the increase in demand is lower than its drop in supply, it results in a drop quantity equilibrium but hikes prices.