Approximate maximum likelihood estimation for stochastic differential equations with random effects in the drift and the diffusion

Consider N independent stochastic processes \((X_i(t), t\in [0,T])\), \(i=1,\ldots , N\), defined by a stochastic differential equation with random effects where the drift term depends linearly on a random vector \(\Phi _i\) and the diffusion coefficient depends on another linear random effect \(\Psi _i\). For these effects, we consider a joint parametric distribution. We propose and study two approximate likelihoods for estimating the parameters of this joint distribution based on discrete observations of the processes on a fixed time interval. Consistent and \(\sqrt{N}\)-asymptotically Gaussian estimators are obtained when both the number of individuals and the number of observations per individual tend to infinity. The estimation methods are investigated on simulated data and show good performances.     

Academic leadership and commercial activities at research institutes: German evidence

This paper focuses on entrepreneurship by academic leaders. With the use of patents, inventions, and spin‐offs to measure commercialization, and directors, research group leaders, and business owners as academic leaders, results, using a sample of more than 2,500 German researchers, show differences across academic leaders and commercialization. Findings for spin‐offs are different from those for patents and inventions. Academic leaders in sciences were more likely to commercialize. Doctoral degrees helped patents by business owners and spin‐offs by group leaders, whereas female business owners and female group leaders faced challenges patenting and inventing, respectively. For business owners, age increased the likelihood of patenting but lowered spin‐offs.     

Modelling spatial regimes in farms technologies

We exploit the information derived from geographical coordinates to endogenously identify spatial regimes in technologies that are the result of a variety of complex, dynamic interactions among site-specific environmental variables and farmer decision making about technology, which are often not observed at the farm level. Controlling for unobserved heterogeneity is a fundamental challenge in empirical research, as failing to do so can produce model misspecification and preclude causal inference. In this article, we adopt a two-step procedure to deal with unobserved spatial heterogeneity, while accounting for spatial dependence in a cross-sectional setting. The first step of the procedure takes explicitly unobserved spatial heterogeneity into account to endogenously identify subsets of farms that follow a similar local production econometric model, i.e. spatial production regimes. The second step consists in the specification of a spatial autoregressive model with autoregressive disturbances and spatial regimes. The method is applied to two regional samples of olive growing farms in Italy. The main finding is that the identification of spatial regimes can help drawing a more detailed picture of the production environment and provide more accurate information to guide extension services and policy makers.     

Policies to increase business tourism income: A dynamic panel data model

This article aims to identify the determinants that influence business tourism income and that may be controlled by economic agents and policy makers of destination countries. For the development of the empirical study, a dynamic panel model by the Generalized Method of Moments (GMM) was estimated using the Gretl 2016a software, and a sample of 122 countries for the period 2002–2013 (12 years) was used. The study reveals that, for the development of policies to stimulate the growth in the short and long-term of business tourism income, countries should develop measures that encourage capital investment in tourism and foreign direct investment.     

Development of a Technology Education Cascading Theory through community engagement site-based support

If teachers are not equipped to teach Technology Education subject nationally and internationally, the continent of Africa will continue to bear the brunt of unsavoury results unless radical interventions are implemented to transform the situation. It is against this background that action research methods became a useful site-based support to empower Technology teachers at three sampled schools from Tshwane South Circuit in Gauteng Province of South Africa. The purpose of this study was to share fresh perspectives on how a sample of Technology teachers responded to content-related classroom practices during reflective action research activities that took place during community engagement contact sessions. These teachers, who are under qualified and unqualified to teach this subject, were engaged in circular and spiral action research cycles. The teachers’ engagement brought forth the development of Technology Education Cascading Theory. It was evident that community engagement activities served as a podium to transform teachers’ teaching of Technology Education and enhance learners’ achievement. The study was underpinned by cooperative enquiry theory and engaged participants in reflective practices of developmental action paradigm. Interaction with Technology Education teachers further revealed that most of them need their schools to budget for this Technology subject they are teaching.     

Retail Mergers and Food Prices: Evidence from France

This paper analyzes the impact of a merger in the French supermarket industry on food prices. Using consumer panel data, we compare the changes in prices for merging and rival firms in affected and comparison markets. We use a novel definition of affected markets when some firms have a local pricing strategy and others a more centralized pricing strategy. We find that prices increase significantly following the merger, and that the merging firms lose market shares. For the rivals, the price increases are larger in local markets, in which concentration increased and differentiation changed after the merger.     

Automatically extracting tourism-related opinion from Chinese social media

Existing tourism-destination investigations of Chinese texts remain weak, and no approach is available to realize Chinese context semantically and automatically. To resolve this, we provide a novel method based on qualitative analysis for studying the online opinions of Chinese tourists regarding the destinations to which they travel. Both traditional and simplified Chinese forums were chosen as the object of study. Spain was selected as a travel destination to evaluate the proposed method. After processing the natural language, unstructured Chinese content is analysed to derive the general sentiment and relevant topics regarding the destination through user comments on social media. The proposed method allows us to understand what tourists are interested in and how they form opinions about tourist destinations.     

The impact of technical consultants on the quality of their clients' products: Evidence from the Bordeaux wine industry

Research summary : Recent research rooted in the resource‐based view of the firm suggests that resources are more likely to create value if they are effectively managed. An underlying assumption of the literature is that firms manage their resources on their own. However, many firms hire consultants to help them do so. In this study, I develop and test hypotheses regarding the impact of technical consultants on the quality of their clients' products. Using data from the Bordeaux wine industry, I find evidence that the use of technical consultants has a positive impact on relative product quality and a negative impact on the extremeness of relative product quality. Moreover, the positive impact of technical consultants on relative product quality is stronger at lower levels of relative resource quality. Managerial summary : Findings from a study in the Bordeaux wine industry indicate that the decision to hire consultants should depend on a firm's strategy. If a firm wants to improve its performance, it should hire consultants. Indeed, the “best practices” of technical consultants are generally more valuable than internally generated knowledge. If a firm wants to achieve outstanding performance, hiring consultants may not be the right decision. Because the “best practices” of technical consultants have more certain performance implications than internally generated knowledge, they decrease the likelihood of extremely low performance. However, their lack of uniqueness also decreases the likelihood of extremely high performance. Finally, the decision to hire consultants should depend on the quality of a firm's resources. Firms with low‐quality resources tend to benefit more from the “best practices” of technical consultants. Copyright © 2016 John Wiley & Sons, Ltd.     

Reconfiguration,restructuring and firm performance: Dynamic capabilities and environmental dynamism

Research summary: Reorganization has been proposed as a key dynamic capability. This study compares the performance outcomes of two forms of reorganization, differing in their pervasiveness: organizational restructuring and organizational reconfiguration. Our dynamic panel data analysis of large U.S. corporations between 1985 and 2004 finds contrasting performance outcomes for these two forms of reorganization: in general, the more pervasive restructuring is associated with positive performance outcomes, while the more limited reconfiguration is associated with negative performance outcomes. However, outcomes vary by environment. Consistent with dynamic capabilities theory, we find evidence that in dynamic environments reconfiguration outcomes turn positive, while restructuring outcomes turn negative. We discuss implications for dynamic capabilities theory and managerial policy. Managerial summary: Firms need to reorganize in order to adapt to change. This study compares the financial performance consequences of two forms of reorganization: organizational restructurings and organizational reconfigurations. Restructurings involve fundamental change in organizational principles and are typically irregular; reconfigurations involve incremental change and are frequent. Examining a set of large U.S. corporations, we find these two forms of reorganization have contrasting financial consequences, depending on context. In the general case, fundamental restructurings have positive consequences, while incremental reconfigurations have negative consequences. However, this general result reverses in specifically dynamic environments, where reconfigurations are positive financially, while restructurings are negative. We conclude that the relative frequency of reconfigurations helps adaptation in dynamic environments. Managers should choose forms of reorganization according to the rate of environmental change. Copyright © 2016 John Wiley & Sons, Ltd.     

Utilizing environmental information and pricing strategies to reduce externalities of tourism: the case of invasive species in the Galapagos

The increase in demand for nature-based tourism brings economic and educational benefits but risks the introduction of invasive species. Increasing the length of tourist trips can better balance these benefits and risks by maintaining revenues while reducing the number of unique contacts with tourists. Changing the relative prices of trips can induce tourists to take longer trips. We hypothesized that providing information about the negative externalities of tourism could improve the effectiveness of such pricing strategies.

We administered one of two discrete choice surveys to tourists considering a trip to the Galapagos. One of the surveys described the Galapagos as a fragile ecosystem susceptible to invasive species; the second described it as a standard nature-based destination. For each sample, we estimated the probability of the tourist choosing a short versus long trip, given the tourist's personal information and trip options presented to him. We then simulated the demand for trips using three pricing strategies. We found that providing information on invasive species significantly increased the efficacy of strategic pricing. We propose using a two-prong approach to tourism management: educate potential tourists about the islands’ vulnerabilities, and simultaneously increase the per-day cost of short trips relative to that of longer trips.