explain law of demand and supply and their factors
Answers
involves the study of how people use limited means to satisfy unlimited wants. The law of demand focuses on those unlimited wants. Naturally, people prioritize more urgent wants and needs over less urgent ones in their economic behavior, and this carries over into how people choose among the limited means available to them. For any economic good, the first unit of that good that a consumer gets their hands on will tend to be put to use to satisfy the most urgent need the consumer has that that good can satisfy.
For example, consider a castaway on a desert island who obtains a six-pack of bottled, fresh water washed up on shore. The first bottle will be used to satisfy the castaway's most urgently felt need, most likely drinking water to avoid dying of thirst. The second bottle might be used for bathing to stave off disease, an urgent but less immediate need. The third bottle could be used for a less urgent need such as boiling some fish to have a hot meal, and on down to the last bottle, which the castaway uses for a relatively low priority like watering a small potted plant to keep him company on the island.
In our example, because each additional bottle of water is used for a successively less highly valued want or need by our castaway, we can say that the castaway values each additional bottle less than the one before. Similarly, when consumers purchase goods on the market each additional unit of any given good or service that they buy will be put to a less valued use than the one before, so we can say that they value each additional unit less and less. Because they value each additional unit of the good less, they are willing to pay less for it. So the more units of a good consumers buy, the less they are willing to pay in terms of the price.
By adding up all the units of a good that consumers are willing to buy at any given price we can describe a market demand curve, which is always downward-sloping, like the one shown in the chart below. Each point on the curve (A, B, C) reflects the quantity demanded (Q) at a given price (P). At point A, for example, the quantity demanded is low (Q1) and the price is high (P1). At higher prices, consumers demand less of the good, and at lower prices, they demand more.
Factors Affecting Demand
So what does change demand? The shape and position of the demand curve can be impacted by several factors. Rising incomes tend to increase demand for normal economic goods, as people are willing to spend more. The availability of close substitute products that compete with a given economic good will tend to reduce demand for that good, since they can satisfy the same kinds of consumer wants and needs. Conversely, the availability of closely complementary goods will tend to increase demand for an economic good, because the use of two goods together can be even more valuable to consumers than using them separately, like peanut butter and jelly.
Other factors such as future expectations, changes in background environmental conditions, or change in the actual or perceived quality of a good can change the demand curve, because they alter the pattern of consumer preferences for how the good can be used and how urgently it is needed.