- If the income elasticity of demand for a product is calculated to be +1.8, which of the following is the most accurate interpretation?
Answer: The product is a normal good, and likely a luxury, because demand increases more than proportionally with income.
A positive income elasticity indicates a normal good. An income elasticity greater than 1 indicates a luxury good, meaning a 1% increase in income leads to a more than 1% (in this case, 1.8%) increase in quantity demanded. A necessity is a normal good with an income elasticity between 0 and 1. An inferior good would have a negative value. A positive value for cross-price elasticity, not income elasticity, indicates a substitute.
- This data suggests that, with respect to the price of sugary soft drinks:
Answer: the cross-price elasticity of demand is positive for bottled water and negative for sweet snacks.
When the price of soft drinks rose, demand for bottled water rose, indicating they are substitutes (positive cross-price elasticity). When the price of soft drinks rose, demand for sweet snacks fell, indicating they are complements (negative cross-price elasticity). We cannot determine the own-price elasticity of soft drinks without knowing how much their quantity demanded changed, nor can we determine if they are normal/inferior without income data.
- The merchant's observation suggests that, for the workers in this region, dried beans and rice are:
Answer: inferior goods, because as income increased, consumers substituted towards more preferred foods.
The scenario describes a rise in income followed by a decrease in the quantity demanded for dried beans and rice. By definition, a good for which demand falls as income rises is an inferior good. The workers are using their higher incomes to purchase other, more desirable types of food. The concept of Giffen goods relates to price changes, not income changes.
- A market researcher is tasked with determining whether a new brand of gourmet ice cream is a 'luxury' item. Which of the following elasticity measures would be most useful for this determination, and what value would support the 'luxury' classification?
Answer: Income elasticity of demand; a positive value greater than 1.
The classification of a good as a luxury or a necessity is determined by its income elasticity of demand. This measures how demand changes as consumer income changes. A luxury good is a type of normal good with an income elasticity greater than 1, meaning demand increases more than proportionally with income. A value between 0 and 1 would classify it as a necessity.
- A calculated cross-price elasticity of demand between smartphones and smartphone cases is -0.7. What is the primary conclusion that can be drawn from this value?
Answer: The two goods are complements, as the negative sign indicates an inverse relationship between one's price and the other's demand.
A negative cross-price elasticity of demand indicates that two goods are complements. This means that as the price of one good (smartphones) falls, the quantity demanded of the other good (cases) rises. The other choices confuse cross-price elasticity with other concepts: substitutes have positive cross-price elasticity, inelasticity refers to own-price elasticity, and normal/inferior classifications relate to income elasticity.
- An economist states that, for most consumers, demand for generic-brand paper towels is 'income inelastic' and has a negative income elasticity. What does this statement imply?
Answer: As income rises, consumers buy a slightly smaller quantity of generic paper towels.
'Negative income elasticity' means the good is inferior, so as income rises, quantity demanded falls. 'Income inelastic' means the absolute value of the elasticity is less than 1, so the percentage change in quantity is smaller than the percentage change in income. Therefore, a rise in income leads to a proportionally smaller (slight) decrease in the quantity purchased.
- This behavior implies that for this consumer:
Answer: both goods are normal, but international vacations have a higher income elasticity of demand than basic groceries.
Normal goods are those for which demand increases as income increases. Both groceries and vacations fit this description. However, goods for which demand increases more than proportionally with income (significant increase) are called luxuries and have an income elasticity greater than 1. Goods for which demand increases less than proportionally (moderate increase) are necessities and have an income elasticity between 0 and 1. Therefore, vacations have a higher income elasticity.
- An analyst finds that the cross-price elasticity of demand for product X with respect to the price of product Y is exactly +1.0. Which statement provides the most accurate and complete interpretation of this finding?
Answer: Products X and Y are substitutes, and a 1% increase in the price of Y leads to a 1% increase in the quantity demanded of X.
The positive sign indicates X and Y are substitutes. The value of +1.0 means that the percentage change in the quantity demanded of X is equal to the percentage change in the price of Y. Elasticity measures the relationship between percentage changes, not absolute unit or dollar changes, which makes distractor D incorrect. Distractor C incorrectly confuses cross-price elasticity with own-price elasticity.
- Which of the following describes the most likely secondary effects, given that gasoline-powered cars are substitutes for EVs and home charging stations are complements to EVs?
Answer: A decrease in the demand for gasoline-powered cars and an increase in the demand for home charging stations.
A drop in the price of EVs will affect related markets. Since gasoline cars are substitutes, a lower EV price will decrease the demand for them (a leftward shift of the demand curve). Since home charging stations are complements, a lower EV price will increase the demand for them (a rightward shift of the demand curve).
- Based on these changes, which statement is most accurate?
Answer: Brand B peanut butter is a substitute for brand A, while brand C jelly is a complement to brand A.
When the price of brand A rises and demand for brand B rises, they are substitutes (positive cross-price elasticity: +8%/+10% = +0.8). When the price of brand A rises and demand for brand C falls, they are complements (negative cross-price elasticity: -5%/+10% = -0.5). The information given is about price changes, not income changes, so we cannot determine if the goods are normal or inferior.
- Which pair of events corresponds to Theory 1 and Theory 2, respectively?
Answer: (Theory 1) The consumer received a raise at work; (Theory 2) A rival cafe offered a discount on its coffee.
Theory 1 (negative income elasticity) implies the good is inferior. A decrease in demand for an inferior good is caused by an increase in income (a raise). Theory 2 (positive cross-price elasticity) implies the other product is a substitute. A decrease in demand for the cafe's coffee would be caused by a decrease in the price of a substitute (a rival's discount).
- If a good is determined to be a 'normal good,' what can be definitively concluded about its income elasticity of demand (Ei)?
Answer: Ei must be a positive number.
The definition of a normal good is any good for which demand increases when income increases. This corresponds to a positive income elasticity of demand (Ei > 0). Normal goods can be further subdivided into necessities (0 < Ei < 1) and luxuries (Ei > 1). Therefore, the only definitive conclusion for all normal goods is that Ei is positive.
- A study finds that a 20% increase in the price of gasoline has no discernible effect on the quantity demanded of premium coffee. The cross-price elasticity of demand between gasoline and premium coffee is likely:
Answer: approximately zero, indicating the two goods are effectively unrelated in consumption.
Cross-price elasticity measures the relationship between two goods. If a price change in one good has no effect on the quantity demanded of another, their cross-price elasticity is zero. This indicates the goods are unrelated. Positive elasticity implies substitutes, and negative implies complements. 'Perfectly inelastic' refers to own-price elasticity of demand, not cross-price elasticity.
- What is the best interpretation of these two figures?
Answer: Both Pepsi and orange juice are substitutes for Coca-Cola, but Pepsi is considered a closer substitute.
A positive cross-price elasticity indicates that goods are substitutes. Since both values are positive, both Pepsi and orange juice are substitutes for Coca-Cola. The magnitude of the elasticity indicates the strength of the relationship. A higher value (+0.8 for Pepsi vs. +0.2 for orange juice) means a closer substitute. Distractor D incorrectly reverses the cause and effect measured by the elasticity.
- This market behavior suggests that the cross-price elasticity of demand for GoQuick rides with respect to the price of RideFast rides is:
Answer: positive, because the two services are clear substitutes for consumers.
The two services are substitutes. When the price of a substitute (RideFast) decreases, the demand for the original good (GoQuick) also decreases. Cross-price elasticity is calculated as (% change in quantity demanded of Good A) / (% change in price of Good B). Here, both the numerator (demand for GoQuick) and the denominator (price of RideFast) are negative, resulting in a positive elasticity. Positive cross-price elasticity is the definition of a substitute good. Distractor A confuses the negative business outcome with the sign of the elasticity.
- An economic research firm observes that as average household incomes in a city rise by 10%, the quantity demanded of generic canned vegetables falls by 5%. What does this finding suggest about generic canned vegetables?
Answer: They are an inferior good, as quantity demanded falls when consumer income rises.
Income elasticity of demand measures how the quantity demanded of a good responds to a change in consumer income. A negative income elasticity (income up, quantity demanded down) indicates the good is an inferior good. Giffen goods relate to price changes, not income changes. Normal goods have a positive relationship with income. Income elasticity is calculated as (% change in quantity demanded) / (% change in income), which is (-5% / +10%) = -0.5. Since the absolute value is less than 1, demand is income inelastic, not elastic.
- A marketing study for a company that sells both video game consoles and video games finds that a 15% decrease in the price of its consoles leads to a 30% increase in the sales of its video games. Which of the following can be concluded from this data?
Answer: The two goods are complements, as indicated by the negative cross-price elasticity of demand.
Cross-price elasticity of demand measures how the quantity demanded of one good responds to a price change in another. When the price of good A falls and the quantity demanded of good B rises, the goods are complements. The calculated elasticity is (+30% / -15%) = -2.0. The negative sign confirms they are complements. A positive sign indicates substitutes. The data is not about the own-price elasticity of games or about income effects (inferior goods).
- What do these two findings imply about the premium leather hiking boots?
Answer: They are a normal good (a luxury) and a substitute for synthetic boots.
Finding (1) relates to income elasticity. Since income fell and sales fell, they are a normal good (positive relationship). The income elasticity is (% change in Q) / (% change in I) = (-15%) / (-5%) = +3.0. Since Ei > 1, they are a luxury. Finding (2) relates to cross-price elasticity. Since the competitor's price rose and the company's sales rose, the goods are substitutes. The cross-price elasticity is (+5%) / (+10%) = +0.5, a positive value indicating substitutes.
- A product's income elasticity of demand is -0.5. Another product's income elasticity is +0.5. Which of the following statements correctly compares these two products?
Answer: The first product is an inferior good and the second is a normal good; the responsiveness of quantity demanded to income changes is the same for both.
The sign of income elasticity determines the type of good: negative for inferior, positive for normal. Thus, the first is inferior and the second is normal. The magnitude (absolute value) indicates responsiveness. Since both have an absolute value of 0.5, which is less than 1, they are both considered income inelastic, and the magnitude of their responsiveness to a percentage change in income is the same.
- The analyst would most likely recommend investing in firms that produce goods with:
Answer: a high positive income elasticity of demand (greater than 1).
Rising incomes will most benefit firms producing luxury goods. Luxury goods are defined as having a high, positive income elasticity of demand (greater than 1), meaning that as income rises by a certain percentage, the demand for these goods rises by an even larger percentage. Negative income elasticity describes inferior goods, whose sales would fall. Low positive elasticity describes necessities, which would see sales grow, but not as rapidly as luxuries.
