Price Elasticity of Supply
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AP Microeconomics › Price Elasticity of Supply
Using the supply data shown for a wheat farm in the very short run (the crop is already planted and harvested quantity cannot be quickly changed), calculate the price elasticity of supply (PES) between Point 1 and Point 2 using the midpoint method.
Supply data (per week):
- Point 1: $P = $8, $Q_s = 100
- Point 2: $P = $10, $Q_s = 110
$PES = 2.50$
$PES = 1.00$
$PES = 0.50$
$PES = 0.40$
$PES = 0.20$
Explanation
The skill here is calculating the price elasticity of supply (PES). PES measures how responsive the quantity supplied is to a change in price, specifically the percentage change in quantity supplied divided by the percentage change in price, indicating producer responsiveness. We use the supply data from Point 1 (P=$8, Qs=100) and Point 2 (P=$10, Qs=110) for the wheat farm in the very short run. Using the midpoint method, PES = [(110-100)/((110+100)/2)] / [(10-8)/((10+8)/2)] = (10/105) / (2/9) = 3/7 ≈ 0.43, which is approximately 0.40 due to rounding in options. A common misconception is that supply is elastic even in the very short run, but time horizon matters—supply is often inelastic when output can't be quickly changed, like with planted crops. To apply this broadly, always use the midpoint formula for accurate arc elasticity between two points. Additionally, compare %ΔQs to %ΔP and consider producer flexibility and time available for adjustments.
Using the supply data shown for a small bakery in the short run (its ovens are already at capacity, so output can only be increased slightly by adding overtime hours), calculate the price elasticity of supply (PES) between Point 1 and Point 2 using the midpoint method.
Supply data (per day):
- Point 1: $P = $10, $Q_s = 40
- Point 2: $P = $12, $Q_s = 44
$PES = 0.10$
$PES = 2.00$
$PES = 0.50$
$PES = 0.20$
$PES = -0.50$
Explanation
The skill here is calculating the price elasticity of supply (PES). PES measures how responsive the quantity supplied is to a change in price, specifically the percentage change in quantity supplied divided by the percentage change in price, indicating producer responsiveness. We use the supply data from Point 1 (P=$10, Qs=40) and Point 2 (P=$12, Qs=44) for the bakery in the short run. Using the midpoint method, PES = [(44-40)/((44+40)/2)] / [(12-10)/((12+10)/2)] = (4/42) / (2/11) = 11/21 ≈ 0.52, which is approximately 0.50 due to rounding in options. A common misconception is that elasticity equals the slope of the supply curve, but PES is a unitless measure that considers relative changes, not just the absolute slope. To apply this broadly, always use the midpoint formula for accurate arc elasticity between two points. Additionally, compare %ΔQs to %ΔP and remember that supply elasticity increases over longer time horizons as producers gain flexibility to adjust output.
Using the supply data shown for a dairy cooperative in the short run (herd size cannot be increased quickly), calculate the price elasticity of supply (PES) between Point 1 and Point 2 using the midpoint method.
Supply data (per day):
- Point 1: $P = $4, $Q_s = 200
- Point 2: $P = $5, $Q_s = 220
$PES = 2.00$
$PES = 0.50$
$PES = 0.44$
$PES = 0.20$
$PES = 1.00$
Explanation
The skill here is calculating the price elasticity of supply (PES). PES measures how responsive the quantity supplied is to a change in price, specifically the percentage change in quantity supplied divided by the percentage change in price, indicating producer responsiveness. We use the supply data from Point 1 (P=$4, Qs=200) and Point 2 (P=$5, Qs=220) for the dairy cooperative in the short run. Using the midpoint method, PES = [(220-200)/((220+200)/2)] / [(5-4)/((5+4)/2)] = (20/210) / (1/4.5) = 3/7 ≈ 0.43, which is approximately 0.44 due to rounding in options. A common misconception is that supply for agricultural goods is always elastic, but in the short run with fixed herd size, it's often inelastic. To apply this broadly, always use the midpoint formula for accurate arc elasticity between two points. Additionally, compare %ΔQs to %ΔP and consider producer flexibility and time available for adjustments.
Using the supply data shown for a rideshare market in the long run (more drivers can enter and vehicles can be acquired), is supply elastic, inelastic, or unit elastic over the range from Point 1 to Point 2? Use the midpoint method.
Supply data (per hour in a city):
- Point 1: $P = $20, $Q_s = 200
- Point 2: $P = $30, $Q_s = 300
Unit elastic, because $PES = 1$ over this range
Perfectly elastic, because firms are price takers
Elastic, because $PES > 1$ over this range
Inelastic, because $PES < 1$ over this range
Perfectly inelastic, because price changes do not affect entry
Explanation
The skill here is determining the price elasticity of supply (PES). PES measures how responsive the quantity supplied is to a change in price, specifically the percentage change in quantity supplied divided by the percentage change in price, indicating producer responsiveness. We use the supply data from Point 1 (P=$20, Qs=200) and Point 2 (P=$30, Qs=300) for the rideshare market in the long run. Using the midpoint method, PES = [(300-200)/((300+200)/2)] / [(30-20)/((30+20)/2)] = (100/250) / (10/25) = 1, classifying supply as unit elastic over this range. A common misconception is that supply is inelastic in markets with many participants, but in the long run, entry and acquisition of resources make it more elastic or unit elastic. To apply this broadly, always use the midpoint formula for accurate arc elasticity between two points. Additionally, compare %ΔQs to %ΔP and consider producer flexibility and time available for adjustments.
Using the supply data shown for a concert venue in the short run (fixed seating capacity limits how many tickets can be supplied for an event), is supply elastic, inelastic, or unit elastic over the range from Point 1 to Point 2? Use the midpoint method.
Supply data (per event):
- Point 1: $P = $40, $Q_s = 500
- Point 2: $P = $50, $Q_s = 550
Perfectly elastic, because quantity supplied changes when price changes
Unit elastic, because $PES = 1$ over this range
Inelastic, because $PES < 1$ over this range
Perfectly inelastic, because capacity is fixed in the short run
Elastic, because $PES > 1$ over this range
Explanation
The skill here is determining the price elasticity of supply (PES). PES measures how responsive the quantity supplied is to a change in price, specifically the percentage change in quantity supplied divided by the percentage change in price, indicating producer responsiveness. We use the supply data from Point 1 (P=$40, Qs=500) and Point 2 (P=$50, Qs=550) for the concert venue in the short run. Using the midpoint method, PES ≈ 0.43, which is less than 1, classifying supply as inelastic over this range. A common misconception is that any change in quantity means elastic supply, but in the short run with fixed capacity like seating, supply is inelastic as producers can't easily increase output. To apply this broadly, always use the midpoint formula for accurate arc elasticity between two points. Additionally, compare %ΔQs to %ΔP and consider producer flexibility and time available for adjustments.
Using the supply data shown for a local bakery’s cupcakes in the next week (the bakery has limited oven capacity and cannot add new ovens in that time), calculate the price elasticity of supply between Point A and Point B using the midpoint method.
Point A: $P = $10 per dozen, $Q_s = 40$ dozen
Point B: $P = $12 per dozen, $Q_s = 48$ dozen
$PES = 0.20$
$PES = -1.00$
$PES = 2.00$
$PES = 0.50$
$PES = 1.00$
Explanation
The skill being tested here is calculating the price elasticity of supply (PES). PES measures how responsive the quantity supplied is to a change in price, calculated as the percentage change in quantity supplied divided by the percentage change in price, reflecting producers' ability to adjust output. In this case, we use the data from Point A (P=$10, Qs=40) and Point B (P=$12, Qs=48) for the bakery’s cupcakes in the next week. Using the midpoint method, the PES is (8/44) / (2/11) = 1, indicating unit elastic supply where the percentage changes are equal. A common misconception is that a steeper supply curve always means inelastic supply, but elasticity considers relative changes, not just the slope. To calculate PES effectively, employ the midpoint formula for accuracy, compare %ΔQs to %ΔP, and factor in time horizons as short-run constraints like fixed oven capacity limit responsiveness. Remember, greater producer flexibility over longer periods typically increases elasticity.
Using the supply data shown for a software firm selling licenses in the next day (digital delivery allows rapid scaling with minimal capacity constraints), is supply elastic, inelastic, or unit elastic over this price range? Use the midpoint method.
Point A: $P = $20 per license, $Q_s = 500$ licenses
Point B: $P = $25 per license, $Q_s = 750$ licenses
Supply is unit elastic over this range.
Supply is perfectly elastic over this range.
Supply is elastic over this range.
Supply is perfectly inelastic over this range.
Supply is inelastic over this range.
Explanation
The skill being tested here is determining the price elasticity of supply (PES). PES measures how responsive the quantity supplied is to a change in price, calculated as the percentage change in quantity supplied divided by the percentage change in price, reflecting producers' scalability. In this case, we use the data from Point A (P=$20, Qs=500) and Point B (P=$25, Qs=750) for the software firm’s licenses in the next day. Using the midpoint method, the PES is (250/625) / (5/22.5) = 1.8, which is greater than 1, classifying supply as elastic over this range. A common misconception is that digital goods always have perfectly elastic supply, but while highly responsive due to low marginal costs, it's not infinite. Use the midpoint formula for consistency, compare %ΔQs to %ΔP to determine elasticity category, and consider factors like digital delivery enabling quick scaling. This approach reveals why some supplies are highly elastic even in short time frames.
Using the supply data shown for a small farm’s strawberries in the next two days (the crop is already harvested, and packing capacity is fixed), is supply elastic, inelastic, or unit elastic over this price range? Use the midpoint method.
Point A: $P = $4 per box, $Q_s = 90$ boxes
Point B: $P = $5 per box, $Q_s = 99$ boxes
Supply is inelastic over this range.
Supply is perfectly inelastic over this range.
Supply is unit elastic over this range.
Supply is perfectly elastic over this range.
Supply is elastic over this range.
Explanation
The skill being tested here is determining the price elasticity of supply (PES). PES measures how responsive the quantity supplied is to a change in price, calculated as the percentage change in quantity supplied divided by the percentage change in price, showing producers' adjustment capabilities. In this case, we use the data from Point A (P=$4, Qs=90) and Point B (P=$5, Qs=99) for the farm’s strawberries in the next two days. Using the midpoint method, the PES is (9/94.5) / (1/4.5) ≈ 0.43, which is less than 1, classifying supply as inelastic over this range. A common misconception is ignoring the time horizon, but in the very short run with fixed harvested crops, supply is often inelastic regardless of price changes. To assess PES, always use the midpoint formula, compare %ΔQs to %ΔP to classify (elastic if >1, inelastic if <1, unit if =1), and consider production flexibility and time available for adjustments. This strategy helps predict how suppliers react in different market scenarios.
Using the supply data shown for a local taxi company in the next hour (the number of licensed drivers currently logged in is fixed, but drivers can slightly extend their shifts), is supply elastic, inelastic, or unit elastic over this range? Use the midpoint method.
Point A: $P = $10 per ride, $Q_s = 200$ rides
Point B: $P = $12 per ride, $Q_s = 220$ rides
Supply is unit elastic over this range.
Supply is elastic over this range.
Supply is inelastic over this range.
Supply is perfectly elastic over this range.
Supply is perfectly inelastic over this range.
Explanation
The skill being tested here is determining the price elasticity of supply (PES). PES measures how responsive the quantity supplied is to a change in price, calculated as the percentage change in quantity supplied divided by the percentage change in price, reflecting producers' immediate adjustments. In this case, we use the data from Point A (P=$10, Qs=200) and Point B (P=$12, Qs=220) for the taxi company in the next hour. Using the midpoint method, the PES is (20/210) / (2/11) ≈ 0.52, which is less than 1, classifying supply as inelastic over this range. A common misconception is assuming very short-run supply is perfectly inelastic, but slight adjustments like extending shifts can allow some responsiveness. Apply the midpoint formula accurately, compare %ΔQs to %ΔP for classification, and factor in time constraints limiting major changes. This technique explains supply behavior in time-sensitive markets.
Using the supply data shown for a microbrewery in the short run (limited fermentation tank capacity restricts rapid expansion), is supply elastic, inelastic, or unit elastic over the range from Point 1 to Point 2? Use the midpoint method.
Supply data (per week):
- Point 1: $P = $5, $Q_s = 1{,}000
- Point 2: $P = $6, $Q_s = 1{,}050
Inelastic, because $PES < 1$ over this range
Unit elastic, because $PES = 1$ over this range
Perfectly inelastic, because quantity supplied does not change when price changes
Elastic, because $PES > 1$ over this range
Perfectly elastic, because brewers can buy more inputs at the market price
Explanation
The skill here is determining the price elasticity of supply (PES). PES measures how responsive the quantity supplied is to a change in price, specifically the percentage change in quantity supplied divided by the percentage change in price, indicating producer responsiveness. We use the supply data from Point 1 (P=$5, Qs=1,000) and Point 2 (P=$6, Qs=1,050) for the microbrewery in the short run. Using the midpoint method, PES ≈ 0.27, which is less than 1, classifying supply as inelastic over this range. A common misconception is that elasticity equals the slope of the supply curve, but PES is a unitless measure that considers relative changes, not just the absolute slope. To apply this broadly, always use the midpoint formula for accurate arc elasticity between two points. Additionally, compare %ΔQs to %ΔP and consider producer flexibility and time available for adjustments.