A GAME THEORETIC APPROACH FOR PRICING OF COMPLEMENTARY PRODUCTS AND DETERMINATION OF INVESTMENT AMOUNT WITH TWO MANUFACTURERS

This article deals with an important topic which is recognized widely in the industrial issues, and investigates a game theory problem in investment games. The problem considers a market with an investor and two manufacturers which are producing complementary products. These two manufacturers intend to purchase new technology; to use technological advantages. New facilities help them reduce their production costs. Market demand is a linear function of price; that increases due to the market price reduction. The two manufacturers in order to buy the new facilities need to use the capital of an investor. For satisfying the investor to invest his/her finance, manufacturers compete with each other. In many investment games, the investor enters into the market and becomes a market member. But in this game, unlike previous studies, the investor won't enter the market directly. He/she just invest in the firm and gains a definite percent of the investment's profit from manufacturers. During problem-solving, the profit of each agent is maximized separately. The game is considered as a Stackelberg-Bertrand game, and assumed the investor as the leader and the manufacturers as followers. To solve the problem, the investor first determines how much to fund in each firm, and then the manufacturers follow investor's decision, and each firm will determine its own price according to the amount of capital gains separately. It is worth noting that the manufacturers make their decision simultaneously. To solve the game, first by Nash equilibrium, the prices of two manufacturers are obtained. Then, according to the equilibrium prices and by Stackelberg equilibrium, the optimal amount of investment in the first firm, as the decision variable of the investor, will be evaluated. The amount of investing in per firm and new demand and also new market prices after the investment has been calculated afterward. At last some managerial insights are derived.