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Social cohesion is an important determinant of community well-being, especially in times of distress such as disasters. This study investigates the phenomena of emergent social cohesion, which is characterized by abrupt, temporary and extensive social ties with the goal of sharing and receiving information regarding a particular event influencing a community. In the context of disasters, emergent social cohesion, enabled by social media usage, could play a significant role in improving the ability of communities to cope with disruptions in recent disasters. In this study, we employed a network reticulation framework to examine the underlying mechanisms influencing emergent social cohesion on social media while communities cope with disaster-induced disruptions. We analysed neighbourhood-tagged social media data (social media data whose users are tagged by neighbourhoods) in Houston, TX, USA, during Hurricane Harvey to characterize four modalities of network reticulation (i.e. enactment, activation, reticulation and performance) giving rise to emergent social cohesion. Our results show that, unlike regular social cohesion, communication history and physical proximity do not significantly affect emergent social cohesion. The results also indicate that weak social ties play an important role in bridging different social network communities, and hence reinforce emergent social cohesion. The findings can inform public officials, emergency managers and decision-makers regarding the important role of neighbourhood-tagged social media, as a new form of community infrastructure, for improving the ability of communities to cope with disaster disruptions through enhanced emergent social cohesion.

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The monetary policy shocks have been widely regarded to have effects on the financial markets. Before the 2008 financial crisis, the Federal Reserve adjusted the federal funds target rate to implement the monetary policy. This paper uses event studies to examine the relationship between the Federal Reserve's interest rate decisions and the asset prices. We find that treasury bills and exchange rates of the developed countries were significantly influenced by the FED's unexpected monetary policy shocks from the year of 1989 to 2008. However, in the same period, exchange rates of the emerging markets responded weakly to the policy surprises. We also have observed that international equity markets and commodity prices were not sensitive to the rate decisions of the Federal Reserve. In addition, Treasury bill yields responded significantly to the anticipated and unanticipated rate decisions in both pre and post FOMC meeting days. We also show that the FED's unexpected monetary policy had significant 5 day post announcement impacts on prices of almost all assets.

Extensive spread of situational information is important for communities in response to crises/disasters. Among various mechanisms affecting the spread of information on social media, influential users play a critical role in enhancing information spread. This study examines the attributes and activities of local influential users as well as their interactions with ordinary users on Twitter during 2017’s Hurricane Harvey. The results show that the influence across local influential users has a scale-free power law distribution and also indicates a major limitation in spreading information caused by insufficient interaction among influential users themselves. The findings suggest that influential users should play a boundary-spanning and brokerage role in addition to their information hub role in order to be more effective in enhancing the spread of situational information.