Final answer:
To calculate the profit from exporting, we subtract the costs from the revenue, while the profit from FDI can be calculated in a similar way. The profit maximizing quantity in the foreign market as a function of the firm's marginal cost is given by (P - c - t) / 2. The profit is decreasing and convex in c, with a slope equal to -Q(c + t). The maximum level of c at which it will be profitable to serve the foreign market by export is when c = P - t. Firms will choose exporting, FDI, or not sell to the foreign market based on the comparison of profits.
Step-by-step explanation:
To calculate the profit from exporting, we need to subtract the costs from the revenue. The revenue can be calculated as the product of the price (P) and the quantity (Q). The cost includes the fixed cost (FX), the variable cost (c) multiplied by the quantity (Q), and the per unit trade cost (t) multiplied by the quantity (Q). The expression for firm profit from exporting is:
Profit = (P - c)Q - (FX + tQ)
To find the profit maximizing quantity in the foreign market, we can differentiate the profit expression with respect to Q, set it equal to zero, and solve for Q. The profit maximizing quantity is:
Q = (P - c - t) / 2
To show that the profit is decreasing and convex in c, we can differentiate the profit expression with respect to c twice. The first derivative represents the slope of the profit function, which is equal to -Q(c + t). The second derivative represents the curvature of the profit function, which is negative. Therefore, the profit is decreasing and convex in c. The maximum level of c at which it will be profitable to serve the foreign market by export is when the profit is zero, so:
c = P - t
For part (b) and (c), the profit from Foreign Direct Investment (FDI) can be calculated as:
Profit = (P - c)Q - FF_DI
Comparing the profit from exporting and FDI, a firm will choose exporting if the profit from exporting is greater than the profit from FDI, a firm will choose FDI if the profit from FDI is greater than the profit from exporting, and a firm will not sell to the foreign market if both profits are negative.