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Microeconomics topic 2. Economics 2013-14. DEMAND. UTILITY. Consumers get satisfaction from goods and services. In economics this is called UTILITY . Three ways to measure utility are: How people react when consuming How much of the product they consume
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Microeconomicstopic 2 Economics 2013-14
UTILITY • Consumers get satisfaction from goods and services. • In economics this is called UTILITY. • Three ways to measure utility are: • How people react when consuming • How much of the product they consume • The price they are willing to pay.
UTILITY • Total utilityis the total satisfaction a consumer will get from consuming a product over a period of time. • Marginal utility is the satisfaction gained from consuming an extra unit of a product. • Total utility is the total of the marginal utilities gained from each unit consumed.
DIMINISHING MARGINAL UTILITY • As someone consumes more of a product the utility gained from each extra unit decreases. • Total utility will continue to increase but at a slower rate, until a maximum is reached. • At this point there is no more satisfaction to be gained from consuming more of the product. Marginal utility will be zero.
If price was £2.00 the consumer would be willing to buy 1 pint because he gets £2 worth of satisfaction. • If the price was £1.80 he would be willing to buy 2 pints. He gets £2 worth of utility from the first pint and £1.80’s worth from the second.
The information can be shown as a demand schedule. • This shows how much a consumer would be willing to buy at a range of prices.
CONSUMER SURPLUS • This is the difference between how much a consumer would be prepared to pay and what is actually paid. • If the price of beer was £1.80 a pint, the consumer would buy 2 pints. He was prepared to pay £2 for the first pint so he gets 20p of utility free, a consumer surplus of 20p
RATIONAL CONSUMER BEHAVIOUR • Economists believe that consumers act in a rational way. • This means they want the best value for money. • Not always possible due to: • imperfect knowledge • Action of other people • Lack of self-control.
Assuming rational behaviour, a consumer will achieve maximum utility when the marginal utility spent on the last unit of each good is equal • This is called EQUI-MARGINAL RETURNS
Demand • Demand (or effective demand) is the quantity of a good or service which a consumer is ABLE and WILLING to buy at a particular price over a certain period of time. • Two types of demand exist: • INDIVIDUAL DEMAND – this is demand of one person for a product. • MARKET DEMAND – this is all the individual demand added together.
THE LAW OF DEMAND • The Law of Demand states: • that as the price of a product increases the demand for it will fall. • This happens for two reasons: • INCOME EFFECT – as the price of a product increases then a person’s real income falls. They are not ABLE to buy the same amount. • SUBSTIUTION EFFECT – as the price of a product increases people will swap to goods that are close to the original product. They are less WILLING to buy.
DEMAND CURVES • The demand curve slopes downward from left to right. • It shows that as price increases the quantity demand falls and vice versa.
PRICE D TYPICAL DEMAND CURVE P1 P D Q1 Q QUANTITY
EXCEPTIONS TO THE LAW OF DEMAND These are goods or services where demand rises as price increases. • Goods of prestige, e.g. designer goods • Assumption of a link between price and quality – higher the price the better the quality. • Expectation of future price rises, e.g. buying shares. • Giffen goods – highly inferior goods, e.g. rice and potatoes.
EXCEPTIONS DEMAND CURVE PRICE QUANTITY
The demand curve for the exceptions to the Law of Demand will slope upwards to begin with. • Eventually though it will resume the normal shape as the income effect kicks in.
IT IS IMPORTANT TO REMEMBER THAT WHEN IT IS PRICE THAT CHANGES IT IS A MOVEMENT ALONG THE DEMAND CURVE. • INCREASE IN PRICE IS A CONTRACTION IN DEMAND. • DECREASE IN PRICE IS AN EXTENSION IN DEMAND. • DEMAND IS SAID TO HAVE RISEN BUT NEVER INCREASED!
CONDITIONS OF DEMAND CETERIS PARIBUS - This is Latin for other things remaining the same. It means that in Economics there is only ever one changing variable at a time. • Price is only one factor that might change the demand of a product, in reality there are many other factors.
OTHER CONDITIONS OF DEMAND • Disposable Income • demand for normal goods/inferior goods • Other goods • price goes up for one/effect on another e.g. Tea/Coffee • Effects on complimentary goods e.g. strawberries and cream • Population • Changes effects demand e.g. age • Tastes and preferences • fashionable goods; advertising campaign effects
EFFECT ON THE DEMAND CURVE • When it is a condition of demand, the demand curve will either shift to the left (decrease in demand) or shift to the right (increase in demand). • REMEMBER CETERIS PARIBUS. If it is a condition of demand price stays the same.
ELASTICITY OF DEMAND • Two types exist: • Price elasticity • Income elasticity
PRICE ELASTICITY OF DEMAND • This measures how responsive demand is to a change in price. • Measures how consumers react to the change of the price of a product. • FORMULA: • PED = % change in demand % change in price
ANSWERS • If PED is greater than 1, demand is very responsive to a change in price. Demand is PRICE ELASTIC • If the PED is less than 1, demand is not responsive to a change in price. Demand is PRICE INELASTIC. • If PED is 0, demand hasn’t changed, then demand is PERFECTLY INELASTIC. • If PED is equal to infinity, demand has changed without a change in price, the demand is PERFECT ELASTIC. • If PED is equal to 1, then demand has UNITARY ELASTICITY.
IMPORTANCE OF PRICE ELASTICITY • Firms really need to know about the elasticity of demand as it helps determine whether they should increase or decrease its prices. • Government need to know about it to determine whether to increase or decrease taxation.
PRICE ELASTIC DEMAND • When demand is price elastic it would be better for the firm to decrease the price. • Elastic demand means that even when there is a small change in price there is a big change in demand. • If the firm was to increase the price the revenue gained from the increase in price would be less than the revenue lost as a result of the drop in demand.
PRICE ELASTIC DEMAND DIAGRAM D P1 Revenue Gain P D Revenue Loss Q1 Q
PRICE INELASTIC DEMAND • In this situation the firm would increase the price. • Inelastic demand means that even when there is a big change in price there is only a small change in demand. • The revenue lost from the small change in demand is outweighed by the revenue gained from the change in price. So total revenue will increase.
PRICE INELASTIC DEMAND DIAGRAM D P1 Revenue Gain P D Revenue Loss Q1 Q
FACTORS AFFECTING PRICE ELASTICITY OF DEMAND • Availability of substitutes – a product with a lot of substitutes will have elastic demand e.g. Nescafe. • Price relative to total spending – e.g. matches • Habit – any product that a consumer considers to be a necessity, then demand will be price inelastic. e.g. Petrol • Fashion – goods which are highly fashionable would be price inelastic e.g. IPhone • Frequency of purchase – products bought regularly would have price inelastic demand e.g. Milk
INCOME ELASTICITY OF DEMAND • This measures the responsiveness of demand to changes in income. • FORMULA: • IED = % change in demand % change in income
ANSWERS • When a person’s income increases by 10% it does not mean that they will buy 10% more than before. • Some commodities will still be unaffordable – 0 income elasticity • Some products they will be no more or no less of e.g. newspaper – 0income elasticity • Some products they may only buy a little more of, e.g. food. These have income inelastic demand. • Some goods and services they will buy a lot more of, e.g. nights out. These have income elastic demand.
ANSWERS • Both income elastic and income inelastic demand are said to have POSTIVE INCOME ELASTICITY • Some products the consumer will buy less of, inferiors goods such as own brands. These have NEGATIVE INCOME ELASTICITY.
IMPORTANCE OF INCOME ELASTICITY • If a seller knows the income elasticity of their products they can predict what would happen to their products if incomes changed and how this would affect their revenue. • Also helps the government predict changes in revenue from taxes on products.