The multilinear extension and the coalition structure value

The multilinear extension has been shown to be an effective tool for computing the Shapley value of an n-person game. We modify here the method for the multilinear extension to calculate the modified coalition structure value (CS-value) for such games.     

What do Airbnb hosts reveal by posting photographs online and how does it affect their perceived trustworthiness?

The use of sellers' personal photographs online is ubiquitous in sharing economy platforms such as Airbnb. This paper addresses two questions. First, what type of personal photos do hosts choose to post on Airbnb? Second, which of the characteristics of their photos affects their perceived trustworthiness? We answer these questions by building a structural equation model of the relation between the characteristics of the photos and the perceived trustworthiness of the hosts. The antecedents of trust in this model were defined based on insights from psychology regarding first impressions. We found that the hosts' visual characteristics (e.g., gender) as revealed in their online photographs affect their perceived trustworthiness both directly and indirectly via attractiveness. We also found that image characteristics, which are not related directly to the traits of the host in the picture (e.g., photograph quality), play a significant role in trust inference. Interestingly, the hosts' choices of their personal photos suggest that they may not be aware of these effects.     

Mean Reversion and Momentum: Another Look at the Price-Volume Correlation in the Real Estate Market

Based on behavioral finance and economics literature, we construct a theoretical framework in which consumers of newly constructed housing units perceive prices to follow a stochastic mean reversion pattern. Given this belief and the high carrying cost maintained by real estate developers, potential buyers opt to either exercise immediately or defer the purchase. We simulate the model within a real option framework by which we show that the optimal time to wait before exercising a purchase is positively related to the price level; hence, a negative (positive) correlation between transaction volume and price level (yield) emerges. Observing data on housing prices and new construction sales in Israel for the years 1998–2007, we apply an adaptive expectation regression model to test consumers’ belief in both mean reversion and momentum price patterns. The empirical evidence shows that while consumers’ demand pattern is simultaneously consistent with the belief in both momentum and mean reversion processes, the effect of the latter generally dominates. Moreover, while the data does not allow for testing the volume and price-level correlation, it does provide support to the positive volume-price yield correlation.     

Institutional logics and innovation in times of crisis: Telemedicine as digital ‘PPE’

How do crises shape digital innovation? In this paper we examine the rapid adoption of digital telemedicine technologies in an Israeli hospital with a focus on the role of the institutional logics held by the stakeholders responding to emerging events. With the onset of COVID-19, the need for social distancing and minimal physical contact challenged and interrupted hospital practices. In response, remote audio-visual functionality of digital technologies were appropriated in different ways, as stakeholders – state actors, managers, health professionals, and family members – sought to improvise and enhance the protection of persons concerned. We show how emerging practices were guided by the dominant institutional logics of stakeholders responding to the crisis. Acting for many as a digital form of ‘personal protective equipment’ (PPE), the technologies enabled diverse action possibilities to become manifest in practices. We add to understanding the role of institutional logics in directing the attention of stakeholders to shape digital innovation in times of crisis.     

Microeconomic determinants of spatial mobility in post-apartheid South Africa: Longitudinal evidence from the National Income Dynamics Study

Migration, important for many areas in development, is strongly related to employment. Debate over labour supply in developing countries frequently hinges on labour migration. This paper examines the determinants of spatial mobility of working-age adults in South Africa, using the first nationally representative longitudinal survey – the National Income Dynamics Study – for 2008–10. The paper outlines the unique advantages of these data for the study of individual mobility – data that open the possibility of a new research project. Specifically, it asks how policy-relevant programmes, such as social transfers and housing assistance, affect migration. This paper finds, on balance, that transfers are negatively correlated with subsequent relocation. Previous migration is also predictive of future migration and both are tightly related to attrition, while there is an increasing but strongly non-linear relationship between income and mobility. Further, we highlight potential pitfalls – including attrition, and definitional difficulties – in the study of migration and illustrate possible solutions.     

A Theory of Gradual Coalition Formation

We study noncooperative multilateral bargaining games, based on underlying TU games, in which coalitions can renegotiate their agreements. We distinguish between models in which players continue to bargain after implementing agreements ("reversible actions") and models in which players who implement agreements must leave the game ("irreversible actions"). We show that renegotiation always results in formation of the grand coalition if actions are reversible, but that the process may otherwise end with smaller coalitions. On the other hand, we show that the grand coalition cannot form in one step if the core of the game is empty, irrespective of the reversibility of actions.     

An experimental study of coordination and learning in iterated two-market entry games

Summary. Tacit coordination in large groups is studied in an iterated market entry game with complete information and multiple market capacities that are varied randomly from period to period. On each period, each player must decide independently whether to enter any of the markets, and if entering, which of the two markets to enter. Across symmetric and asymmetric markets, we find remarkable coordination on the aggregate level, which is accounted for by the Nash equilibrium, together with considerable individual differences in frequency of entry and decision rules. With experience, the decisions of most players converge to decision rules with cutoff values on the combined market capacity that determine whether or not to enter but not which of the two markets to enter. This latter decision is determined probabilistically by the differential market capacities. The aggregate and individual results are accounted for quite well by a reinforcement-based learning model that combines deterministic and probabilistic elements.     

Multi-stage voting, sequential elimination and Condorcet consistency

A class of voting procedures based on repeated ballots and elimination of one candidate in each round is shown to always induce an outcome in the top cycle and is thus Condorcet consistent, when voters behave strategically. This is an important class as it covers multi-stage, sequential elimination extensions of all standard one-shot voting rules (with the exception of negative voting), the same one-shot rules that would fail Condorcet consistency. The necessity of repeated ballots and sequential elimination are demonstrated by further showing that Condorcet consistency would fail in all standard voting rules that violate one or both of these conditions.     

Veto power in committees: an experimental study

Veto power consists of the right of one or more players to unilaterally block decisions but without the ability to unilaterally secure their preferred outcome. Our experiment shows that (i) committees with a veto player take longer to reach decisions (are less efficient) and generate less consensus than without a veto player, (ii) veto power substantially enhances proposer’s power, and (iii) non-veto players are substantially more willing to compromise than veto players. We relate our results to the theoretical literature on the impact of veto power as well as to concerns about the impact of veto power in real-life committees.     

immigration and the collapse of communism

Will Western Europe have to deal with a flood of emigrants from the East? Jonathan Eyal, of the Royal United Services Institution, argues that the West should not be unduly affected.