- The US President has announced plans to impose a βBuild in USAβ policy that would impose a tariff of π = 50% on imports to the US of products made outside the US. At present (Period 0), it is not known whether he will make good on those threats., but it is believed that the tariff will be imposed with probability π = 60%. A British firm is the worldβs only supplier of diet Irn-Bru, which is a (strangely) popular product among the Presidentβs US supporters. Currently, the firm manufactures the beverage at its plant in Turnberry, Scotland. The product costs πΆ = Β£2 per unit to make; shipment to the US costs an additional π = Β£8 per unit. The inverse demand curves for the UK and US markets are:
πππΎ = π΄ππΎ β π΅ππΎ β πππΎ = 50 β 2 β πππΎ
πππ = π΄ππ β π΅ππ β πππ = 200 β πππ
The fixed cost of building a plant in the US is πΉππ = Β£10000; the average variable cost
of production using this plant is πΆππ
(π) = πΌ β π½π = 10 β π. The riskless rate of return

2
is ππ = 5%. The companyβs stock is currently trading at π0 = Β£100; if the tariff is imposed it will fall to ππ = Β£68.55; otherwise it will rise to πππ = Β£147.17.
[For avoidance of doubt, the firm faces no tariff in Period 0, but may face a tariff in Periods 1,2,β¦ If it does face a tariff, it will compute a new price and quantity for its exports to the US market. There are no recurrent fixed costs (beyond the one-off cost of constructing a US plant). For each situation, find the quantity produced and corresponding price using the inverse demand curve π(π) and total cost curve ππΆ(π) by maximising π(π)π β ππΆ(π) w.r.t. π. The situations are: US plant supplying US market; UK plant supplying US market without tariff; UK plant supplying US market with tariff; and UK plant supplying UK market. The US plant, if built, will only be used to supply the US market and starts producing from the period in which it is built.]
- Find the profit-maximising prices and quantities for the two markets in period 0 and the corresponding Period 0 profits (8 marks)
- using the UK plant and
- building a plant in the US to supply the US market.
- If the President implemented the βbuild in USAβ policy in period 0, would the firm build the US plant?
- Suppose that i) with probability π, the tariffs will be imposed starting in Period 1 and lasting forever ( with probability 1 β π the tariffs will never be imposed),
ii) the US plant has to be built today (or never) and iii) the UK and US (if built) plants would operate forever. Would the plant be built today? What is the WACC? (12 marks)
- Suppose the firm could buy an option to delay the decision until Period 1 (when the tariff choice will be known), but doing so would raise the cost of constructing the US plant to πΊππ. Find the value of the option as a function of πΊππ. (8 marks)
- How would your answers to b and c change if the tariffs were randomly imposed
in each future period, but the US plant could only be built in Period 0 (as in part b) or either in Period 0 or Period 1 (as in part c)? For the purposes of this question, you should assume that:
- There will be no tariff in Period 0;
- The tariff will be applied in Period 1 with probability π;
- If the tariff is applied in Period 1, it will be applied in all subsequent periods with probability ππ > π; and
- If the tariff is not applied in Period 1, it will be applied in all subsequent periods with probability ππ· < π.
How does this increased instability affect the value of the option to delay? (12 marks)
- A Canadian firm is hiring an executive to run its US export business. It also has to approve the advertising budget requested by the new executive. The profitability of the advertising will depend on the extent to which US customers are willing to buy Canadian products; this will be known by the executive after they take up the post, but is not known to the firm. You may assume that the profitability of the advertising is given by a random variable π, uniformly distributed on the interval [π0, π0 + π]. The firm believes the profitability of setting a budget of π΅ is ππΉ(π΅|π) = 1 + ππ΅ β π΅2. However, the executive also gets kickbacks from US media outlets for placing ads; if perfectly-informed about advertising effectiveness, the executive would value π΅ at ππ(π΅|π) = 1 + (π + π½)π΅ β π΅2 where π½ is a non-negative constant. After the executive has had time to study the market, the firm asks the executive to report on advertising effectiveness (π) and purchases the quantity that maximises the firmβs expected utility given this report. Other than ππ(π΅|π), the executive gets no remuneration.
- How would you set up this problem? Can the executive be sure of purchasing the optimal quantity (according to their preferences)? If so, how? If not, why not? How does your answer depend on the size of π½? (6 marks)
- Suppose that the minimum effectiveness is π0 = 25%, π = 50% and that
π½ = 5%. Find the βbabbing equilibriumβ for this situation β what budget will the firm approve and what expected utilities will the firm and the executive get? (10 marks)
- Now construct a two-part equilibrium β depending on the report from the executive, the approve either a low budget π΅πΏππ or a high budget π΅π»ππβ. At what reported level of effectiveness will the firm switch its order size, and what are the values of π΅πΏππ and π΅π»ππβ? (10 marks)
- Now consider a more detailed budgeting process; the executive reports
π, which may or may not be the true value π. The firm has announced a βmenuβ {ππ, π1, β¦ , ππΎ}, where π0 = ππ and ππΎ = ππ + π and corresponding budget levels {π΅π, π΅1, β¦ , π΅πΎ} β if the report π β [ππ, ππ+1) then the approved budget level is π΅π, which maximises the firmβs expected utility conditional on the true value being uniformly distributed over [ππ, ππ+1). Derive the conditions under which the executive will report honestly and show that there is a maximum value of πΎ which is inversely related to the size of π½. You need not derive an explicit equation relating the maximum πΎ to π½ but can show this by example. Does a higher πΎ lead to higher expected utility for the firm? For the executive? (12 marks)
- What would happen if, instead of trusting the executive, the firm announced that they would accept any report leading to a budget less than or equal to a ceiling π΅Μ ; otherwise, theyβd only authorise a budget of
π΅Μ . Find the executiveβs optimal reporting strategy (π as a function of the true state π). Is there an optimal value for π΅Μ ? If so, what is it? How do the expected utilities compare to those found in parts b and c? (12 marks)
- Finally, how would your answer to e change if the firm announced that it would accept any report leading to a budget less than or equal to π΅Μ , but
would audit any report that would lead to a larger budget. If the auditor found that the true value π β π, the firm would fine the executive π½π΅, where π΅ is the budget corresponding to the report π (in other words, the budget that maximises ππΉ(π΅|π))? (10 marks)