What is meant by "demand" and what is a "demand curve"?

The demand curve is a foundational concept in economics, as it illustrates the relationship between the price of a product or service and the quantity demanded by consumers. Imagine plotting a graph with price on the vertical axis and quantity on the horizontal axis; the demand curve would typically slope downward, indicating that as the price falls, more people are willing and able to make a purchase. However, this curve isn't just a theory; it's grounded in daily consumer behavior. For example, if a popular smartphone's price drops, we generally see an increase in sales, reflecting the downward slope of the demand curve.

This curve can shift due to factors like changes in income, tastes, or the prices of related goods. An inward shift indicates a decrease in demand at any given price, possibly caused by decreased consumer income. An outward shift, on the other hand, would suggest an increase in demand. Understanding these shifts is crucial for businesses and policy-makers because they influence strategies for pricing, marketing, and inventory management.

At its core, the law of demand is a principle that guides consumer choices in the marketplace. It posits a simple, yet powerful idea: if all other factors remain equal, the higher the price of a good, the less people will demand it, and conversely, the lower the price, the more people will want to buy it. This inverse relationship is more than just theoretical; it reflects the everyday decisions that buyers make as they consider their limited budgets versus their needs and wants.

For instance, during a sale, we often witness consumers buying more products because the prices are lower. It's the law of demand in action, influencing everything from supermarket deals to big-ticket items like cars. Marketers and business owners use this law to set promotional strategies that attract customers, like 'buy one get one free' offers. Additionally, understanding how the law of demand works is essential when analyzing market trends and making pricing decisions.

Price elasticity of demand is a measure that tells us just how much the quantity demanded will change when the price of a product changes. It's about sensitivity. If a product has high price elasticity, small changes in price can lead to significant changes in quantity demanded. This is typical for luxury goods or items with many substitutes. For example, when the price of a specific brand of juice goes up, customers might quickly switch to another brand. This product would have high price elasticity.

In contrast, inelastic demand indicates that quantity demanded is largely unaffected by price changes. This is common with necessities like medication; even if the price increases, people still need to purchase them. Calculating the price elasticity of demand involves a simple formula: the percentage change in quantity demanded divided by the percentage change in price. This ratio is key for businesses to determine optimal pricing strategies and also helps governments predict the impact of taxation on goods.