Bottled Water Price Ceiling after a Typhoon
After a typhoon damages two reservoirs, a district council imposes a temporary maximum price of HK$8 per 500 ml bottled water. Before the intervention, the market price was HK$5 and 20,000 bottles were sold daily. At HK$8, local suppliers are willing to supply 22,000 bottles per day, while consumers demand 35,000. Shops ration by queueing: office workers can arrive early, but elderly residents and shift workers cannot. A parallel market quickly emerges at HK$14 per bottle, and some shops bundle water with snacks to raise the effective price. The council must decide whether to keep, tighten, or remove the ceiling after one week. Retailers claim the ceiling protects low-income households; consumer groups say queues and resale make water less accessible. The council has no budget for a subsidy and cannot import water quickly because roads remain blocked.
1. Using the figures, explain why the HK$8 ceiling creates a shortage. Identify two non-price rationing mechanisms in the setup and explain one distributional effect of each.
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At HK$8, quantity demanded is 35,000 bottles per day and quantity supplied is 22,000, so the shortage is 13,000 bottles per day. The ceiling is binding because the post-typhoon market-clearing price is above HK$8; the parallel market price of HK$14 is evidence that some buyers are willing to pay much more than the ceiling.
Two non-price rationing mechanisms are queueing and bundling. Queueing allocates water to those who can arrive early, so office workers with flexible hours gain while elderly residents and shift workers may lose. The time spent queueing is a real cost and is not counted in the HK$8 price. Bundling water with snacks raises the effective price: a buyer who wants only water must pay for a snack too. This favours consumers with higher incomes and may bypass the spirit of the ceiling. The parallel market also rations by willingness to pay and by access to supply; sellers or their contacts capture the HK$6 gap between the ceiling and resale price, while buyers face search and enforcement risks.
2. The council asks whether removing the ceiling would make low-income households worse off. Discuss with reference to elasticity and the parallel market.
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Removing the ceiling would allow the legal price to rise toward the market-clearing level. The parallel market price of HK$14 suggests that the ceiling price of HK$8 is well below what some buyers would pay. If low-income households have inelastic demand for bottled water because it is a necessity, a higher price would increase their total expenditure and make them worse off in money terms.
However, the ceiling already imposes costs on low-income households: they may queue for hours, pay HK$14 in the parallel market, or buy unwanted snacks to obtain water. If shift workers cannot queue, the ceiling may not help them at all. Removing the ceiling could reduce queueing and illegal resale, and competition among shops might push the legal price below the HK$14 parallel market price. The distributional outcome therefore depends on who bears the queueing cost and on demand elasticity. Removal alone is not clearly better for low-income households; a targeted cash transfer or subsidised distribution would protect them better than a universal price ceiling.
3. Evaluate whether the ceiling improves allocative efficiency.
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Allocative efficiency requires that the marginal benefit of the last bottle equals its marginal cost. At the ceiling quantity of 22,000 bottles, the parallel market price of HK$14 indicates that some consumers value an extra bottle at about HK$14, while suppliers would produce it at a marginal cost below that. The ceiling prevents these mutually beneficial trades, so it creates a deadweight loss.
Queueing also uses real resources: hours spent waiting are not transferred to anyone and could have been used for work or leisure. Bundling distorts consumers' choices and may waste snacks. The parallel market uses resources for search, risk-bearing, and enforcement. These are additional efficiency costs. The ceiling may improve equity if it guarantees some water at HK$8 to a target group, but queueing is not targeted at low-income households. On balance, the ceiling is likely to reduce allocative efficiency; a targeted voucher or emergency release of public stock would address equity with smaller efficiency loss.