2,167 research outputs found
The dynamics of closeness and betweenness
Although both betweenness and closeness centrality are claimed to be important for the effectiveness of someones network position, it has not been explicitly studied which networks emerge if actors follow incentives for these two positional advantages. We propose such a model and observe that network dynamics differ considerably in a scenario with either betweenness or closeness incentives compared to a scenario in which closeness and betweenness incentives are combined. Considering social consequences, we find low clustering when actors strive for either type of centrality. Surprisingly, actors striving for closeness are likely to reach networks with relatively low closeness and high betweenness, while this is the other way round for actors striving for betweenness. This shows that in both situations the network formation process implies a social dilemma in which the social optimum is not reached by individual optimizing.networks, closeness centrality, betweenness centrality, actor utility, network dynamics, social dilemma
Heterogeneity and Increasing Returns May Drive Socio-Economic Transitions
There are clear benefits associated with a particular consumer choice for
many current markets. For example, as we consider here, some products might
carry environmental or `green' benefits. Some consumers might value these
benefits while others do not. However, as evidenced by myriad failed attempts
of environmental products to maintain even a niche market, such benefits do not
necessarily outweigh the extra purchasing cost. The question we pose is, how
can such an initially economically-disadvantaged green product evolve to hold
the greater share of the market? We present a simple mathematical model for the
dynamics of product competition in a heterogeneous consumer population. Our
model preassigns a hierarchy to the products, which designates the consumer
choice when prices are comparable, while prices are dynamically rescaled to
reflect increasing returns to scale. Our approach allows us to model many
scenarios of technology substitution and provides a method for generalizing
market forces. With this model, we begin to forecast irreversible trends
associated with consumer dynamics as well as policies that could be made to
influence transition
- ā¦