Network formation with closeness incentives

We study network formation in a strategic setting where every agent strives for short paths to the other agents. The main parameter of our model is the marginal rate of substitution between network benefits and linking costs. We provide boundaries of stable networks for increasing and decreasing marginal returns. The formulated model stands in strong relation to the famous connections model (Jackson and Wolinsky ‘96): we show that for certain parameter values both models induce the same network structures.

A note on Condorcet consistency and the median voter

We discuss to which extent the median voter theorem extends to the domain of single-peaked preferences on median spaces. After observing that on this domain a Condorcet winner need not exist, we show that if a Condorcet winner does exist, then it coincides with the median alternative ('the median voter'). Based on this result, we propose two non-cooperative games that implement the unique strategy-proof social choice rule on this domain. --

The Road Less Traveled: Funders' Advice on the Path to Nonprofit Sustainability

(With apologies to Robert Frost, The Road Not Taken, 1920.) As part of the Capital Ideas symposium co-hosted by the Hauser Center for Nonprofit Organizations at Harvard University and the Nonprofit Finance Fund in March, 2007, an online survey was conducted about funder practices that support nonprofit sustainability. This article highlights the survey findings and the advice that funders offered from their own experiences as paths to greater nonprofit strength. Rather than a qualitative analysis of funding initiatives, this article presents guidance to the field from the field, as funders grappling with how best to strengthen the long term health of their grantees reflect on their works in progress. This article then goes a step further by annotating these lessons learned with the additional perspective offered from just four of the ten draft funding principles that have evolved from the Capital Ideas symposium with the hope of encouraging more funders to consider these principles and practices in their own work. The Capital Ideas survey generated 48 profiles of funding approaches, practices and strategies that support nonprofit organizational capacity building, long term financial health and or programmatic improvement. The lessons funders learned from those initiatives informed ten funding principles that were introduced at the Capital Ideas symposium on March 15, 2007 at Harvard University. Four of those draft principles, outlined below, offered concepts that resonated throughout the profiles and are offered as key steps for funders to consider as they reflect upon their own giving practices. These principles include: Understand when youre building or buying, and fund accordingly. Actively pool resources when more funds are required to achieve results. Minimize the transaction costs for grantees and funders of applying for and reporting on grants. Fund at the organizational rather than the programmatic level, even when your primary interest is in one program. This publication is Hauser Center Working Paper No. 40. The Hauser Center Working Paper Series was launched during the summer of 2000. The Series enables the Hauser Center to share with a broad audience important works-in-progress written by Hauser Center scholars and researchers

Under-connected and Over-connected Networks

Since the seminal contribution of Jackson & Wolinsky 1996 [A Strategic Model of Social and Economic Networks, JET 71, 44-74] it has been widely acknowledged that the formation of social networks exhibits a general conflict between individual strategic behavior and collective outcome. What has not been studied systematically are the sources of inefficiency. We approach this omission by analyzing the role of positive and negative externalities of link formation. This yields general results that relate situations of positive externalities with stable networks that cannot be “too dense” in a well-defined sense, while situations with negative externalities tend to induce “too dense” networks.Networks, Network Formation, Connections, Game Theory, Externalities, Spillovers, Stability, Efficiency

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

Under-connected and over-connected networks

Since the seminal contribution of Jackson & Wolinsky 1996 [A Strategic Model of Social and Economic Networks, JET 71, 44-74] it has been widely acknowledged that the formation of social networks exhibits a general conflict between individual strategic behavior and collective outcome. What has not been studied systematically are the sources of inefficiency. We approach this gap by analyzing the role of positive and negative externalities of link formation. We find general results that relate situations of positive externalities with stable networks that cannot be "too dense" in a well-defined sense, while situations with negative externalities, tend to induce "too dense" networks.networks, network formation, connections, game theory, externalities, spillovers, stability, efficiency

An Investigation of the Effects of Self-Efficacy on STEM Implementation

In order to equip students with the 21st Century skills necessary for today’s society, STEM education must be properly implemented in school curricula (Lamb, Akmal, & Petrie, 2015). To do so, it is important for teachers to possess both proficient knowledge of the subject matter and confidence towards the implementation of STEM. A person’s beliefs about their ability is known as their self-efficacy (Bandura 1997). Related to education, Bandura notes that this self-efficacy affects a teacher’s views on their ability to handle tasks, obligations, and challenges related to a challenge (1997). Additionally, numerous studies indicate that this self-efficacy in turn affects actual performance in the classroom (Katzenmeyer & Lawrenz, 2006; Smith, Douglas, & Cox, 2009). With this in mind, this study was designed to survey teachers in the Northwest Arkansas area (Washington and Benton counties) and determine the extent to which STEM education and project-based learning is being implemented. In order to gain insight into the research questions, the researcher distributed the STEM Efficacy Survey Instrument to a random pool of elementary educators over a two week period in February 2021. This instrument surveyed elementary teachers on their previous background in STEM, their feelings towards their ability to implement STEM, and their actual implementation of STEM. From this research, the researcher concluded that higher training in STEM resulted in higher confidence in teachers ability which in turn resulted in higher rates of implementation. More research on the affects of self-efficacy on STEM implementation needs to be conducted in order to gain a more complete picture of what measures should be taken in order to increase teacher self-efficacy, and in turn increasing implementation