Optimal prepayment and default rules for mortgage-backed securities

We study the optimal stopping problems embedded in a typical mortgage. Despite a possible non-rational behaviour of the typical borrower of a mortgage, such problems are worth to be solved for the lender to hedge against the prepayment risk, and because many mortgage-backed securities pricing models incorporate this suboptimality via a so-called prepayment function which can depend, at time t, on whether the prepayment is optimal or not. We state the prepayment problem in the context of the optimal stopping theory and present an algorithm to solve the problem via weak convergence of computationally simple trees. Numerical results in the case of the Vasicek model and of the CIR model are also presented. The procedure is extended to the case when both the prepayment as well as the default are possible: in this case, we present a new method of building two-dimensional computationally simple trees, and we apply it to the optimal stopping problem.     

Risk and Capital Structure in the Regulated Firm

This paper studies the role of capital structure in a regulated firm. We show that it affects the prices set by the regulator, the expected price being lower the higher the proportion of debt finance. However, when debt is increased beyond a certain level, the benefit of lower expected prices is offset by their increased variability. We also study the socially preferred capital structure. This is such that consumers carry some risk, in the form of higher prices in adverse economic conditions.     

Price rigidity and market-clearing: a conceptual clarification

This article tests the view (derived from Hicks and Patinkin)that non-market clearance may be caused by slow adjustment (‘processrigidity’). There are models where market-rationing ispresent and derives from some form of rigidity, but this rigiditycannot be considered as process rigidity. It is similarly possibleto accommodate the idea of process rigidity within the Marshallianresearch programme. What is missing is that market-rationingmight be its corollary. The reason such a causal link is oftenbelieved to exist lies in a generic use of the concept of rigidity,used to designate alternative and incompatible phenomena: ‘exogenousend-state rigidity’ and ‘equilibrium end-state rigidity’,as well as process rigidity. It is true that these first twoforms of rigidity create market rationing. The belief that slowadjustment also generates market rationing results from theunwarranted extension to process rigidity of conclusions whichare only valid for the first two.     

The Visible Hand of corporate entrepreneurship in state-owned enterprises: a longitudinal study of the Spanish National Postal Operator

This study explores how the corporate entrepreneurship (CE) of state-owned enterprises (SOEs) evolves under varying conditions of state ownership and control, laws and norms, and competence in the market. For this purpose, we present a longitudinal case study focused on the Spanish postal operator Correos using qualitative archival data and interviews. Our results indicate that the willingness and capacity of an SOE to act entrepreneurially depends critically on its degree of autonomy from the state and on the extent to which its legal and market environments increase its dynamism, complexity, and hostility. We also show that the development of CE in an SOE may lead to improved service quality, operational efficiency, and business specialization; facilitate its market positioning; and foster its sustainability through the exploration and exploitation of strategic alliances that can increase its business scope.

     

POLICY MAKING FOR INDUSTRIAL COMPETITIVENESS IN PORTUGAL - Patterns of change in a traditional bureaucracy

In Portugal the EEC membership represented a major change in Portuguese Administration functioning. This article uses the new institutionalism approach and the concept of path-dependence to analyse the change in the functioning of a central directorate reponsible for industrial policy. It argues that despite the external pressures for change has altered the directorate operations, there are patterns of continuity which are path-dependent. The response to change shows institutional reproduction in traditional features which is partly due to the reluctance to change traditional methods and partly because of the routines, procedures and norms embedded in the culture.     

Shedding new light on the relationship between contextual ambidexterity and firm performance: An investigation of internal contingencies

This research investigates four key factors that influence the relationship between contextual ambidexterity and firm performance: two knowledge exchange elements (i.e., informational justice and task conflict) and two aspects of the internal competitive environment (i.e., resource competition and reward interdependence). These components define a firm's ability to convert its ambidextrous posture into enhanced performance. A sample of Canadian-based firms shows that the contextual ambidexterity–firm performance relationship is amplified at higher levels of informational justice and reward interdependence but suppressed at higher levels of task conflict and resource competition. The authors discuss the study's implications as well as future research directions.     

Market novelty, competence-seeking and innovation networking

Studies of innovation networking have frequently been concerned with the occurrence of dyadic relationships and with their apparent impact on simple measures of firm-level innovation outputs. This paper takes a more detailed look by analyzing the connection between different types of innovation and forms of networking. Based on the market novelty of innovation outcomes and the extent to which innovation activities require new competences, four types of innovation are identified. It is proposed that these types correlate with various innovation network dimensions, including the volume of networks, the strength and content of ties, and the specificity of ties. Drawing on survey data of 594 innovations realized by Dutch small firms, it is observed that the requirement to access new competences for innovation correlates positively with the number of network partners involved. We also note more subtle connections between types of innovation and networking, including that novel innovation outputs correlate with using network partners as a source of inspiration, whilst new competences associate with networking for knowledge capital. In the latter case, these activities also draw on new and intended ties relatively often, i.e. network partners which are actively sought out for the specific contributions they may make to the innovation process. Finally, innovation which is simultaneously new-to-the market and requires new competences uses strong ties relatively often. Implications for innovation policy and practice are discussed.     

From Returns to Tweets and Back: An Investigation of the Stocks in the Dow Jones Industrial Average

A sizeable percentage of investors are using social media to obtain information about companies (Cogent Research [2008]). As a consequence, social media content about firms may have an impact on stock prices (Hachman [2011]). Various studies utilize social media content to forecast stock market-related factors such as returns, volatility, or trading volume. The objective of this article is to investigate whether a bidirectional intraday relationship between stock returns and volatility and tweets exists. The study analyzed 150,180 minute-by-minute stock price and tweet data for the 30 stocks in the Dow Jones Industrial Average over a random 13-day interval from June 2 to June 18, 2014 using a BEKK-MVGARCH methodology. Findings indicate that 87% of stock returns are influenced by lagged innovations of the tweets data, but there is little evidence to support that the direction is reciprocal, with only 7% of tweets being influenced by lagged innovations of the stock returns. Results further show that the lagged innovations from 40 percent of stock returns affect the current conditional volatility of the tweets, while 73 percent of tweets affect the current conditional volatility of stock returns. Moreover, there is strong evidence to suggest that the volatility originating from the returns to the tweets persists for 33 percent of stocks; the volatility originating from the tweets to the returns persists for 73 percent of stocks. Last, 53 percent of stocks exhibit both immediate and persistent impacts from returns to tweets, while 90 percent of stocks exhibit both immediate and persistent impacts from tweets to returns. These results may help traders achieve superior returns by buying and selling individual stocks or options. Also, asset and mutual fund managers may benefit by developing a social media strategy.     

Testing the Influence of Substitute Sites in Nature Valuation by Using Spatial Discounting Factors

This paper investigates the effect of nearby nature substitute sites on preferences for nature restoration. Contrary to prior studies, we use a respondent-centric approach to control for substitute sites. We assess each respondent-specific spatial context by computing densities of nature substitute sites within various ranges from each respondent’s home. This approach considers the use and non-use values of nature together. Data from three similar discrete choice experiments carried out in Flanders (Belgium) are compared. Different spatial discounting factors are tested to explore how the substitution effect behaves with regard to distance. Latent class analyses are performed to account for preference heterogeneity among respondents. We observe divergent behaviours across groups of respondents. The “distance-to-substitutes” affects how respondents gauge substitute sites. We find a significant influence of the squared average buffer distance but this effect varies in sign across case studies and classes of respondents. Our results demonstrate that individual-specific GIS data can significantly improve the representation of the spatial context and the transferability of value functions. However, the roles played by preference heterogeneity and nature perception on respondents’ capacity to value nature still deserves further attention in future research.     

短期事件对旅游的影响:以中国SARS危机为例

通过回顾近年来世界各国发生的短期危机对旅游产生的影响，重点分析2003年的SARS疫情给中国经济特别是旅游业造成的重大损失，讨论了不同的短期危机对旅游的不同影响以及旅游在危机后的不同恢复时间。旅游业对短期危机缺乏足够的防御能力，但通常能较为迅速的走上复苏之路。在这个过程中，适当的危机管理措施和有效的恢复策略是十分重要和不可或缺的。