Using the option theory in the valuation of unsold stock

Since there is not a firm without a stock of unsold goods, the study of this phenomenon is an issue of great importance. Indeed, firms face the stock of unsold goods that they want to clear at the end of the market period. The latter has an impact on not only on the firm's production process, but also on the economy growth. In this context, how to value the stock of unsold goods and when should the firm clears it? This doctoral work aims to answer to this fundamental question from the standpoint of economics. For this purpose, we must first determine at which price a firm can clear its stock of unsold goods and then determine when it should have recourse to selling-off market or clearance sales? The first part of this thesis is dedicated to a review of the literature, both related to management and marketing science, but also to economics. The second part focuses on an original model of unsold goods' stock valuation which is adapted to the microeconomic hedging methods used in finance (including options where the demand is uncertain). Results show that it is possible to provide a hedge against the risk of a stock of unsold goods. On the one hand, the theory is adapted to the case of supply and on the other hand, it fits the case of a stock of unsold goods. From the theoretical point of view, the results of numerical simulations illustrate the way this method works in practice for different cases. The third part is more general since it introduces two intertemporal original models under the monopolistic market structure. There are two types of consumers, depending on the degree of their sensitiveness to the display of goods. Consumers who are relatively strongly sensitive to the display of goods choose to buy a part from it. Furthermore, the monopoly chooses both the price and the quantity of displayed goods in order to maximize its profit. Under certain or uncertain demand, it always emerges a stock of unsold goods. The monopoly can sell the stock of unsold goods, either directly to consumers who are insensitive to the display of goods, or to the selling-off firm. Endogenous selling-off market is then studied.