Demand and Supply together decide how markets work. Demand shows how much consumers want to buy, while supply shows how much producers want to sell. Both depend on several factors that change buyers’ and sellers’ behaviour. When these factors change, the entire demand or supply level also changes.
Determinants of Demand:
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Price of the Product
Price is the most important factor affecting demand. When price rises, people buy less because their budget becomes limited. When price falls, they buy more because the product becomes affordable. This is known as the law of demand. For example, if the price of rice increases, families reduce consumption or shift to cheaper options. If the price falls, they buy more. Thus, price has an inverse relationship with quantity demanded, assuming all other factors remain unchanged in the market.
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Income of Consumers
Income decides purchasing power. When income increases, people buy more goods, especially normal goods like clothing, electronics and packaged foods. When income decreases, demand for these goods falls. However, for inferior goods like low-quality rice or old transport services, demand may rise when income falls. In India, demand for premium products rises during periods of higher income or job growth. Therefore, income plays a direct or inverse role depending on the type of product.
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Taste and Preferences
Consumer taste changes due to culture, fashion, lifestyle, health awareness and advertising. When people like a product more, demand increases even if price stays the same. When taste shifts away, demand falls. For example, demand for smartphones, organic food and fitness products has increased due to lifestyle changes. Similarly, demand for outdated gadgets has reduced. Taste is influenced by trends, social media and seasonal factors, making it a strong non-price determinant of demand.
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Prices of Related Goods
Related goods include substitutes and complements. When the price of a substitute rises, the demand for the main product increases. For example, if tea becomes expensive, people buy more coffee. For complementary goods, when the price of one increases, demand for the related product decreases. If petrol price rises, demand for cars may fall. Thus, the demand for a product depends on price changes in other related goods that consumers use together.
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Future Expectations
Consumers make decisions based on future expectations of price, income or availability. If people expect prices to rise soon, they buy more today, increasing demand. If they expect prices to fall, they delay purchases, reducing demand. During festival seasons or inflation periods, demand rises because people fear future price hikes. Expectations about income, such as job security or bonuses, also influence demand. This determinant plays an important role in markets that change quickly, like electronics.
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Number of Buyers
Demand increases when the number of buyers in the market increases. Demand decreases when the number of buyers reduces. Population growth, migration, urbanisation and demographic changes directly influence the total demand. For example, large Indian cities have more demand for housing, transport and food due to high population. Tourist areas experience higher demand during peak seasons. A bigger consumer base leads to higher total market demand, even if individual consumption remains the same.
Determinants of Supply:
- Price of the Product
Price strongly influences how much producers supply. When price increases, producers increase supply because higher prices give higher profit. When price decreases, supply falls as profit becomes low. This follows the law of supply. For example, if the price of onions rises, farmers try to supply more next season. A direct relationship exists between price and supply. Producers continuously track prices before deciding production levels in order to maximise income.
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Cost of Production
Cost determines how expensive it is to produce goods. If costs increase due to higher raw material prices, labour costs or fuel expenses, producers supply less because profit decreases. If production becomes cheaper, supply increases because it becomes easier to produce more. For example, when fuel prices rise, transportation costs go up and supply falls. When the government reduces GST or offers subsidies, cost reduces and supply expands. Thus, cost has an inverse relationship with supply.
- Technology
Better technology helps producers make goods faster, cheaper and with fewer resources. When technology improves, supply increases because production becomes more efficient. In agriculture, better seeds, irrigation and machinery increase crop supply. In industries, automation, new machines and improved processes raise output. Poor or outdated technology reduces supply because production becomes slow and expensive. Technology is one of the strongest determinants of supply because it directly affects productivity and efficiency.
- Prices of Related Goods
Producers choose between different goods based on profitability. When the price of a related good rises, producers may shift resources to that product, reducing supply of the original good. For example, if the price of cotton increases, farmers may grow more cotton instead of other crops. Similarly, if sugarcane price rises, land shifts away from wheat. Producers always compare profit opportunities. Therefore, the price of related goods strongly affects supply decisions.
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Government Policies
Government decisions such as taxes, subsidies, import rules and regulations affect supply. Higher taxes increase cost, reducing supply. Subsidies lower cost and encourage more production. In India, fertilizer subsidies and MSP support increase agricultural supply. Strict regulations, price controls or environmental rules may reduce supply. Supportive policies increase production by making business easier, while discouraging policies reduce supply because producers face higher risks and expenses.
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Natural Factors
Natural conditions such as rainfall, climate, temperature, drought, flood and storms affect supply, especially in agriculture. Good weather increases supply because crops grow well. Poor weather reduces supply because production is affected. In industries, natural factors affect availability of raw materials. For example, weak monsoon reduces the supply of rice and wheat, while good monsoon increases overall output. Natural disasters interrupt transport and production, reducing supply.
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Number of Sellers
When more sellers enter the market, supply increases because more products become available. When sellers exit due to losses or competition, supply decreases. For example, when new smartphone brands enter India, total supply rises. When small factories shut down, supply reduces. The number of sellers shows how competitive the market is. More sellers lead to greater supply, while fewer sellers reduce market availability.