Narrow Results

Why does diffusion sometimes show cascade phenomena but at other times is impeded? In addressing this question, we considered a threshold model of diffusion, focusing on the formation of a critical mass, which enables diffusion to be self-sustaining. Performing an agent-based simulation, we found that the diffusion model produces only two outcomes: Almost perfect adoption or relatively few adoptions. In order to explain the difference, we considered the various properties of network structures and found that the manner in which thresholds are arrayed over a network is the most critical factor determining the size of a cascade. On the basis of the results, we derived a threshold arrangement method effective for generation of a critical mass and calculated the size required for perfect adoption.

The information propagation on the social network has been an important research topic, with a focus on the significant influence of individual behaviors. The marginal utility behavior can affect the process of information propagation. But most previous research ignore it. Besides, the process can also be influenced by limited-contact capacity, which increase the complexity of networks. In this paper, the marginal utility behavior model on the single-layer network with limited-contact capacity is proposed first. Then the edge-based compartmental (EBC) method is used to explore the novel information propagation mechanism. Through experiments, it was found that when individuals show an increasing marginal utility behavior, with the propagation probability increasing, the final spreading scope shows a discontinuous increase pattern by weakening behavior. However, the final spreading scope shows no outbreak by strengthening behavior. In contrast, when individuals show a diminishing marginal utility behavior, with the propagation probability increasing, the final spreading scope shows a continuous increase pattern by strengthening. Nevertheless, the final spreading scope shows a discontinuous increasing by weakening. What’s more, the limited-contact capacity and the degree distribution heterogeneity can also change the information propagation pattern. Besides, the experimental results are in agreement with the theoretical results.

In this paper we present a study of the influence of heterogeneity on the clustering of preferential attachment networks. The study is performed by the numerical analysis of the threshold preferential attachment model, a generalization of the Barabási—Albert model to heterogeneous complex networks. Heterogeneous networks are characterized by the existence of intrinsic properties of the nodes which induce specific affinities in their interactions. We analyze the influence of the affinity parameters on the distribution of degree-averaged clustering coefficients of the threshold model. We show that the introduction of heterogeneity increases the inverse correlation between clustering and connectivity of the nodes, inducing a power-law scaling in the clustering distribution. We also show that a higher level of heterogeneity increases the overall clustering coefficients irrespective of the node degrees. These results exhibit a better agreement of the extended model with the empirical observations of clustering in real networks.

In this paper, we construct and analyze a mathematically reasonable and simplest population dynamics model based on Mark Granovetter’s idea for the spread of a matter (rumor, innovation, psychological state, etc.) in a population. The model is described by a one-dimensional difference equation. Individual threshold values with respect to the decision-making on the acceptance of a spreading matter are distributed throughout the population ranging from low (easily accepts it) to high (hardly accepts). Mathematical analysis on our model with some general threshold distributions (uniform; monotonically decreasing/increasing; unimodal) shows that a critical value necessarily exists for the initial frequency of acceptors. Only when the initial frequency of acceptors is beyond the critical, the matter eventually spreads over the population. Further, we give the mathematical results on how the equilibrium acceptor frequency depends on the nature of threshold distribution.

We examine whether and how firm characteristics, including firm size and liquidity, affect the relation between employee stock option (ESO) grants (as proxied by disclosed ESO expenses) and firm value. We also investigate how the implementation of a new share-based compensation recognition rule affects the pricing effect of ESOs. Prior studies have provided mixed results concerning how ESOs affect firm value. We argue that their findings could be attributable to self-selection and a non-uniform ESO-share price relation. We use the threshold model to address our research questions after controlling for self-selection bias. We find that markets tend to positively price ESOs in the case of firms characterized by large size and low liquidity. In addition, we find that after the new rule came into effect, ESOs became positively associated with firm value. These results are congruent with ownership and symbolic value theories, the lifecycle stages hypothesis and the contention that an ESO expensing policy enhances the quality of financial statements.

This study takes the initiative to make a link between empirical aspect of an economy and theoretical part of it. Investigating econometric findings, the current study has taken advantages of profound analytical discussions to justify which school of thought describe liberalization phenomena and its relevant side effects. This paper presents an investigation into the effects of financial openness on stock market efficiency in emerging markets after controlling for certain level of institutional development. The results demonstrate that there is a threshold effect in the liberalization–efficiency relationship. Specifically, we found that the impact of financial liberalization on informational efficiency of the stock market was positive and significant only after a certain threshold level of institutional development had been attained. Below this level, the effect of financial liberalization on stock market efficiency was negative. This finding suggests that the positive effects of financial liberalization on informational efficiency are contingent on the level of institutional development, thus supporting the idea that financial liberalization embedded within a sound institutional framework has the capacity to enhance stock market efficiency. The conclusion that the governance concept, emphasized in econometric findings, is implicit in the definition of neoliberalism can be considered as one of the contributions of the study.