In the past decade a lot of attention has been devoted to the option valuation approach to i~vestments in financial economics. This theory provides a fl exible way of incorporating uncertainty and irreversibility into the making of the investment decision. The primary purpose of this study is to extend the contingent claim approach by introducing a strategic dimension into the investment decision. In particular we focus on the case where an investor may be preempted by one or more competitors, and where there is an advantage of acting first. Secondly, we apply the strategic options approach to some important areas in financial economics, such as corporate investment under uncertainty, corporate default , market micro-structure . and the timing of arbitrage. Apart from illustrating the wide applicability and relevance of the techniques, this also clarifies some important issues in financial economics. 'Option Games' (jointly written with William Perraudin) describes a way of incorporating strategic behaviour and asymmetric information into optimal stopping decisions under uncertainty. vVe derive optimal stopping rules when each agent's payoff is affected by the actions of other agents and these latter are of unknown type. 'Strategic Sequential Investments: an Application to Preemptive Patenting' derives the optimal investment rules for an incumbent and a challenger who both have an option to patent an innovation with stochastic payoff. We find that the optimal trigger rule is determined by a trade-off between the benefit of waiting to invest and the need to act quickly due to the competitive threat. In particular, we demonstrate that both the strategic Marshallian break-even investment trigger and the trigger obtained by the option valuation approach are in fact limit_ing polar cases of the strategic investment trigger developed in this paper. We then extend the model to a two-stage sequential investment situation where the first and the second stage respectively consist of patenting and launching the product. The model allows us to explain and analyse the phenomenon of sleeping patents. It appears that sleeping patents are more likely to occur when interest rates are low, price volatility is high or when the first stage_ cost is small relative to the second stage cost. 'Creditor Races and Contingent Claims' (jointly written with William Perraudin) presents a simple pricing model in which two debt-holders with incomplete information about each other's type decide when to foreclose on a financially-distressed firm. 'The Timing of Arbitrage: an Options Approach' presents a continuous-time modei for the timing of riskless arbitrage when the mispricing between two equivalent portfolios varies stochastically through time under the exogenous impact of liquidity trades and when there is a persistent prospect that the arbitrage bubble can 'burst'. The model endows the arbitrageur with n options to do arbitrage. When endogenously determined arbitrage bounds a re violated one or more arbitrage trades bring asset prices back within the bounds. The model is extended to the case where there are two competing arbitrageurs who have incomplete information about each other's type.

Le domaine de notre recherche est la décision stratégique au sein des organisations. Plus précisément il s'agit de l'aide à la prise de décision stratégique et de la problématique de l'acquisition des informations utiles pour de telles décisions. D'un côté les ‘informations de terrain' issus des contacts entre personnes, des réunions professionnelles, etc. demeurent essentielles pour les dirigeants. D'un autre côté les journaux quotidiens nationaux et internationaux fournissent un volume considérable de données que l'on peut qualifier de données brutes (Raw data). Mais, outre ces sources classiques, le recueil des informations a évolué de façon considérable avec l'avènement des technologies de l'information et notamment de l'Internet pour ce qui concerne dans notre recherche. Nous avons choisi le domaine concernant l'acquisition des informations de terrain fournies par les journaux nationaux quotidiens : les journaux quotidiens colombiens pour ce qui concernera notre étude empirique. Pour acquérir cette information nous avons proposé sur la base d'une recherche du type « Action Design Research », de concevoir, de construire et d'expérimenter un artéfact permettant de détecter des signaux faibles potentiels issus des données extraites d'Internet et qui aideraient les dirigeants de l'entreprise à découvrir et comprendre leur environnement. L'artéfact a été conçu et construit en deux phases utilisant des concepts théoriques liés à la surcharge de données, à la veille stratégique notamment la VAS-IC® (Veille Anticipative Stratégique – Intelligence Collective) et sur les caractéristiques souhaitables des systèmes informatisés d'aide à la décision stratégique. Après sa construction, l'artéfact a été expérimenté sur un terrain permettant d'évaluer son effectivité. Cette expérimentation a permis d'améliorer nos connaissances sur la pertinence des données numériques dans le processus de la prise de la décision. Les décideurs impliqués ont également pu d'intégrer des nouvelles pratiques adaptées à leurs besoins d'information. / Our research area is around the strategic decision within organizations. More precisely, it is applicable as an aid for strategic decision-making and detecting useful information for such decisions. On the one hand, the ‘information from the field' from the contacts between individuals, business meetings, etc. is always essential for managers. On the other hand, national and international newspapers can provide a considerable volume of data that can be defined as the raw data. However, besides these classical sources, gathering information has changed dramatically with the advent of information technology and particularly internet that is related to our research. We chose the area for the acquisition of ‘information from the field' provided by the national daily newspapers: the Colombian newspaper which concerns to our empirical study. In order to detect weak signals of potential internet base issues which help managers to discover and understand their environment, we proposed a research based on “Action Design Research” type and then applied for designing, building and testing an artifact to gain the required information. The artifact has been designed and built in two phases that is included of using theoretical concepts about the data overload, environmental scanning particularly the “anticipatory and collective environmental scanning model” (VAS-IC®) and the desirable characteristics of strategic decision making support systems. After its construction, the artifact applied to real experimentation that has allowed us to evaluate its effectiveness. Afterwards, we improved our knowledge about the relevance of digital data in the decision making process. The results of all the involved decision makers have been able to integrate these new practices into their information needs.