Watching online videos interactively: the impact of media capabilities in Chinese Danmaku video sites

In China, the implementation of a Danmaku social media system to sustain and raise user interest in online video sites is an increasingly widespread phenomenon. Danmaku technology is used to display users’ messages in written text on the online video stream. Little is known about the effects of this form of interactive enhancement. The aim of this empirical study is to evaluate the evolving media capabilities of the Danmaku system and their effects on users’ perceptions of interactivity and their intentions to continue using Danmaku. We draw on media synchronicity theory and apply it to a stimulus-organism-response model. Using this framework, we hypothesize that the media capabilities of the Danmaku system, namely its transmission velocity, parallelism, symbol sets, rehearsability, and reprocessability, elicit increased interactivity, which influences users’ instantaneous intentions to share and to continue the use of the Danmaku system. The results showed that both users’ instantaneous intention to share and their intention to continue to use were significantly affected by the perceived interactivity. Unlike the results of previous studies, our findings showed that all five media capabilities positively affected the users’ perceptions of interactivity. The potential theoretical and practical implications of our findings are discussed.     

Population Density is a Key Factor in Declining Human Fertility

In studying the complex determinants of human fertility, social scientists have given little attention to population density, although reproduction has been shown to be density-dependent for a wide variety of other species. Using fixed effects models on the time series of 145 countries and controlling for key social and economic variables, we find a consistent and significant negative relationship between human fertility and population density. Moreover, we find that individual fertility preferences also decline with population density. These findings suggest that population density should be included as a variable in future studies of fertility determinants.

David and Goliath: causes and effects of coopetition between start-ups and corporates

Coopetition (collaboration between competitors) among young firms (i.e. start-ups) and larger, more established firms (i.e. corporates) may be beneficial for both partners as each party typically has something to offer that is missing in the other. Start-ups often develop innovative ideas, are flexible and agile, willing to take risks, and aspire to achieve high growth, but they tend to lack the required resources, capabilities, and knowledge due to their newness and smallness. Corporates have resources, routines, and experience that enable them to work efficiently but lack a certain innovation capability. Research has suggested that coopetition represents an opportunity for start-ups facing restrictions in resources, while corporates benefit from start-ups’ innovative ideas. However, it is yet unknown whether start-ups and corporates engage in coopetition with each other and, if so, how and why they do this. This study seeks to fill this void by exploring the motives of coopeting start-ups and corporates, how they manage their coopetitive relationship, and what implications occur including potential benefits and risks. We present a multiple case study based on qualitative data collected through 70 interviews with Austrian-based start-ups and corporates representing 35 coopetitive partnerships. Discussing the findings based on our data, we propose relationships concerning coopetition and its role to enlarge resource- and technology-bases as well as its role in the development of dynamic capabilities.     

Demography,Education, and Democracy: Global Trends and the Case of Iran

Reconstructions and projections of populations by age, sex, and educational attainment for 120 countries since 1970 are used to assess the global relationship between improvements in human capital and democracy. Democracy is measured by the Freedom House indicator of political rights. Similar to an earlier study on the effects of improving educational attainment on economic growth, the greater age detail of this new dataset resolves earlier ambiguities about the effect of improving education as assessed using a global set of national time series. The results show consistently strong effects of improving overall levels of educational attainment, of a narrowing gender gap in education, and of fertility declines and the subsequent changes in age structure on improvements in the democracy indicator. This global relationship is then applied to the Islamic Republic of Iran. Over the past two decades Iran has experienced the world's most rapid fertility decline associated with massive increases in female education. The results show that based on the experience of 120 countries since 1970, Iran has a high chance of significant movement toward more democracy over the following two decades.     

Strategic Shared Leadership and Organizational Dynamic Capabilities

We propose that the purposeful sharing of strategic decisions and the process of making and taking those between the dominant coalition of an organization (Strategic Shared Leadership or SSL thereafter), initiated and supported by a focal strategic leader or small team, engenders Organizational Dynamic Capabilities (ODCs) though the transfer of individually-residing DCs within the SSL team, the transformation -co-creation of novel ones and their embeddedness-institutionalization within the organization. It also enhances organizational cognition which mediates the relationship by enriching co-created ODCs and their capacity to deliver reliably change through sensing, seizing and reconfiguring. Accordingly, SSL serves as a co-creator and key predictor of the emergence of ODCs. This helps address the challenges of DCs to marry stability with change, be predictable and to be capable of predicting.     

Confidence Corridors for Multivariate Generalized Quantile Regression

We focus on the construction of confidence corridors for multivariate nonparametric generalized quantile regression functions. This construction is based on asymptotic results for the maximal deviation between a suitable nonparametric estimator and the true function of interest, which follow after a series of approximation steps including a Bahadur representation, a new strong approximation theorem, and exponential tail inequalities for Gaussian random fields. As a byproduct we also obtain multivariate confidence corridors for the regression function in the classical mean regression. To deal with the problem of slowly decreasing error in coverage probability of the asymptotic confidence corridors, which results in meager coverage for small sample sizes, a simple bootstrap procedure is designed based on the leading term of the Bahadur representation. The finite-sample properties of both procedures are investigated by means of a simulation study and it is demonstrated that the bootstrap procedure considerably outperforms the asymptotic bands in terms of coverage accuracy. Finally, the bootstrap confidence corridors are used to study the efficacy of the National Supported Work Demonstration, which is a randomized employment enhancement program launched in the 1970s. This article has supplementary materials online.     

Flexible Tweedie regression models for continuous data

Tweedie regression models (TRMs) provide a flexible family of distributions to deal with non-negative right-skewed data and can handle continuous data with probability mass at zero. Estimation and inference of TRMs based on the maximum likelihood (ML) method are challenged by the presence of an infinity sum in the probability function and non-trivial restrictions on the power parameter space. In this paper, we propose two approaches for fitting TRMs, namely quasi-likelihood (QML) and pseudo-likelihood (PML). We discuss their asymptotic properties and perform simulation studies to compare our methods with the ML method. We show that the QML method provides asymptotically efficient estimation for regression parameters. Simulation studies showed that the QML and PML approaches present estimates, standard errors and coverage rates similar to the ML method. Furthermore, the second-moment assumptions required by the QML and PML methods enable us to extend the TRMs to the class of quasi-TRMs in Wedderburn's style. It allows to eliminate the non-trivial restriction on the power parameter space, and thus provides a flexible regression model to deal with continuous data. We provide an R implementation and illustrate the application of TRMs using three data sets.     

Monitoring means and covariances of multivariate non linear time series with heavy tails

In this paper, the focus is on sequential analysis of multivariate financial time series with heavy tails. The mean vector and the covariance matrix of multivariate non linear models are simultaneously monitored by modifying conventional control charts to identify structural changes in the data. The considered target process is a constant conditional correlation model (cf. Bollerslev, 1990 Bollerslev, T. (1990). Modeling the coherence in short-run nominal exchange rates: A multivariate generalized ARCH model. Rev. Econ. Stat. 72:498–505.[Crossref], [Web of Science ®] , [Google Scholar]), an extended constant conditional correlation model (cf. He and Teräsvirta, 2004 He, C., Teräsvirta, T. (2004). An extended constant conditional correlation GARCH model and its fourth-moment structure. Economet. Theory 20:904–926.[Crossref], [Web of Science ®] , [Google Scholar]), a dynamic conditional correlation model (cf. Engle, 2002 Engle, R.F. (2002). Dynamic conditional correlation: A simple class of multivariate GARCH models. J. Bus. Econ. Stat. 20(3):339–350.[Taylor &; Francis Online], [Web of Science ®] , [Google Scholar]), or a generalized dynamic conditional correlation model (cf. Capiello et al., 2006 Capiello, L., Engle, R., Sheppard, K. (2006). Asymmetric correlations in the dynamics of global equity and bond returns. J. Financial Economet. 4(4):537–572.[Crossref] , [Google Scholar]). For statistical surveillance we use control charts based on residuals. Further, the procedures are constructed for t-distribution. The detection speed of these charts is compared via Monte Carlo simulation. In the empirical study, the procedure with the best performance is applied to log-returns of the stock market indices FTSE and CAC.