Social nudges for vaccination: How communicating herd behaviour influences vaccination intentions

Objectives: This Registered Report attempted to conceptually replicate the finding that communicating herd immunity increases vaccination intentions (Betsch, et al., 2017, Nat. Hum. Behav., 0056). An additional objective was to explore the roles of descriptive social norms (vaccination behaviour of others) and the herd-immunity threshold (coverage needed to stop disease transmission).Design: An online experiment with a 2 (herd-immunity explanation: present vs. absent) x 3 (descriptive norm: high vs. low vs. absent) x 2 (herd-immunity threshold: present vs. absent) between-subjects fractional design.Methods: Sample consisted of 543 people (aged 18–64) residing in the United Kingdom. Participants first received an explanation of herd immunity emphasising social benefits (protecting others) in both textual and animated-infographic form. Next, they were faced with fictitious information about the disease, the vaccine, their country’s vaccination coverage (80% or 20%), and the herd-immunity threshold (90%). Vaccination intention was self-rated.Results: Compared to the control, communicating social benefits of herd immunity was effective in increasing vaccination intentions (F(1,541) = 6.97, p = .009, Partial Eta-Squared = 0.013). Communicating the descriptive norm or the herd-immunity threshold alongside the herd-immunity explanation demonstrated no observable effect.Conclusion: Communicating social benefits of herd immunity increased self-reported vaccination intentions against a fictitious disease, replicating previous findings. Although this result is positive, the practical relevance may be limited. Further research into the effect of social nudges to motivate vaccination is required, particularly with respect to the recent pandemic context and varying levels of vaccine hesitancy.

Short Term and Long Term Herding Prospects: Evidence from Pakistan Stock Exchange

The present research intends to examine the herd behaviour of investors in the Pakistan Stock Exchange (PSX). Herd behaviour in stock market is sometimes based on fundamental information, which causes quick price adjustments to new information and leads to efficient markets. Still, sometimes it is not dependent on fundamental information and results in price instability. Herding can be a short term phenomenon, but sometimes a longer time span can provide favourable outcomes for the occurrence of herd behaviour. Considering these diverse views, intraday, daily, weekly, and monthly stock prices of 528 companies listed in the PSX have been used to calculate stock returns. Market-wide herd measure, i.e. CSAD, has been used to compute the herd behaviour. Data has been investigated for autocorrelation, heteroscedasticity, and stationarity issues. Findings revealed that herding did not exist in PSX, but some sectors showed this behaviour. Herd behaviour was more likely to exist at a daily level. The tendency of occurrence of the herding phenomenon gradually decreases at intraday and weekly levels. However, herding cannot be taken as a long term phenomenon as just a single sector was evidenced about its existence at the monthly level. Herding is an inherent phenomenon that is very difficult to eliminate from the stock market completely. However, knowledge and information sharing can guide investors to improve this behaviour Keywords: Herd Behaviour, Behavioural Finance, Return Dispersions, Pakistan Stock Exchange, CSAD

Mathematical study on a dynamical predator-prey model with constant prey harvesting and proportional harvesting in predator

A dynamical predator-prey model with constant prey harvesting, proportional harvesting in predator has been studied. The square root func- tional response also has been incorporated in the system to describe the prey herd behaviour, assuming the average handling time is zero. The existence and the local stability of equilibria of the system have been discussed. It is examined that, two types of bifurcation occur in the system. The two types of bifurcations have been analyzed, and it has been found by analyzing the saddle-node bifurcation that, there is a maximum sustainable yield. It is ob- served that if harvesting rate is greater than the maximum sustainable yield, the prey population abolish from the system and then extinction of the preda- tor population happen. But if harvesting rate is lesser than the maximum sustainable yield, the extinction of the prey population can not be possible. By analyzing the Hopf bifurcation, it is obtained that, there exists an unstable limit cycle around the interior equilibrium point. Several numerical simulations are performed to check the results.

COVID-19, bitcoin market efficiency, herd behaviour

PurposeUnlike previous crisis where investors tend to put their assets in safe havens like gold, the recent coronavirus pandemic is characterised by an increase in the Bitcoin purchasing described as risk heaven. This paper aims to analyse the Bitcoin dynamics and the investor response by focusing on herd biases. Therefore, the main objective of this work is to study the degree of efficiency through multifractal analysis in order to detect herd behaviour leading to build the best predictions and strategies.Design/methodology/approachThis paper develops a novel methodology that detects the presence of herding biases and assesses the inefficiency of Bitcoin through an inefficiency index (MLM) by using statistical indicators defined by measures of persistence. This study, also, investigates the nonlinear dynamical properties of Bitcoin by estimating the Multifractal Detrended Fluctuation Analysis (MFDFA) leading to deduce the effect of COVID-19 on the Bitcoin performance. Besides, this work performs an event study to capture abnormal changes created by COVID-19 related events capable to analyse the Bitcoin market response.FindingsThe empirical results of the generalized Hurst exponent GHE estimation indicates that Bitcoin is multifractal before this pandemic and becomes less fractal after the outbreak. Using an efficiency index (MLM), Bitcoin is found to be more efficient after the pandemic. Based on the Hausdorff topology, the authors showed that this pandemic has reduced the herd bias.Research limitations/implicationsThe uncertainty of COVID-19 disease and the lasting of its duration make it difficult to make the best prediction.Practical implicationsThe main contribution of this study is the evaluation of the Bitcoin value after the COVID19 outbreak. This work has practical implications as it provides new insights on trading opportunities and social reactions.Originality/valueTo the authors’ knowledge, this work represents the first study that analyses the Bitcoin response to different events related to COVID-19 and detects the presence of herding behaviour in such a crisis.

Design Three Trading Strategies Based on Overconfidence, Loss Aversion, and Herd Behaviour

<p>There is a basic assumption in the field of economics, which is people are rational. It might be taught in the first class of the principle of economics. However, this assumption could hardly be applied to the real world since people can be affected easily sometimes, especially when they cope with their assets. Thus, with combination of psychology and academic finance, behavioural finance aims to understand the effects influencing investors’ decision-making. This paper will discuss some effects which can be commonly seen in the real world, overconfidence, loss aversion, and herd behaviour included.</p>