Time Lags Reduce Supply Elasticity

Steps:

• Recall PES measures percentage change in quantity supplied divided by percentage change in price; higher PES means more responsive supply.
• Compare production processes: manufacturing allows quick adjustments via labor or machinery, raising PES.
• For fresh vegetables, supply depends on agricultural cycles, limiting short-run responsiveness.
• Identify factor causing lower PES for vegetables: delays in planting and harvesting prevent rapid output increases.

Why D is correct:

• PES decreases with longer time lags in production (per elasticity formula, responsiveness falls when supply adjustments are time-constrained by biological/seasonal factors).

Why the others are wrong:

• A: Importing alternatives would increase overall PES, not explain lower domestic vegetable PES.
• B: This describes the upward-sloping supply curve, which applies equally to both goods and doesn't differentiate elasticity.
• C: A horizontal supply curve implies perfectly elastic supply (infinite PES), contradicting lower elasticity for vegetables.

Final answer: D