Dynamics and near-optimal control in a stochastic rumor propagation model incorporating media coverage and Lévy noise

The appearance of rumors intensifies people’s panic and affects social stability. How to control the spread of rumors has become an important issue which is worth studying. In order to more accurately reflect the actual situation in the real world, a stochastic model incorporating media coverage and Lévy noise is proposed to describe the dynamic process of rumor propagation. By introducing two control strategies of popular science education and media coverage in an emergency event, an near-optimal control problem that minimizes the influence and control cost of rumor propagation is proposed.Sufficient conditions for near-optimal control of the model are established by using a Hamiltonian function. Then the necessary conditions for near-optimal control are obtained by using the Pontryagin maximum principle. Finally, the effect of popular science education, media coverage and Lévy noise on rumor propagation process control is verified by numerical simulation.

Dynamics of a stochastic rumor propagation model incorporating media coverage and driven by Lévy noise

With the development of information technology,rumors propagate faster and more widely than in the past.In this paper,a stochastic rumor propagation model incorporating media coverage and driven by Lévy noise is proposed.The global positivity of the solution process is proved,and further the basic reproductive number R_(0) is obtained.When R_(0)<1,the dynamical process of system with Lévy jump tends to the rumor-free equilibrium point of the deterministic system,and the rumor tends to extinction;when R_(0)>1,the rumor will keep spreading and the system will oscillate randomly near the rumor equilibrium point of the deterministic system.The results show that the oscillation amplitude is related to the disturbance of the system.In addition,increasing media coverage can effectively reduce the final spread of rumors.Finally,the above results are verified by numerical simulation.

Repairing damaged reputations through targeted poverty alleviation:Evidence from private companies’strategies to deal with negative media coverage

When negative media coverage causes reputational crises,companies must find suitable tools to repair their reputation and reverse their negative image.As a CSR activity with political-and livelihood-related implications,targeted poverty alleviation may be an effective tool.Using data on negative media coverage of Chinese A-share private listed companies,we examine whether companies engage in targeted poverty alleviation in response to reputational crises caused by negative media coverage.We find that negative media coverage leads private companies to engage more actively and intensively in targeted poverty alleviation because of the significant increase in public attention to the bad news.These companies must urgently rebuild their positive image using targeted poverty alleviation to resolve their public opinion crisis.Further analyses suggest that original and in-depth negative media coverage is more likely to cause companies’active participation in targeted poverty alleviation.In addition,negative media coverage is more likely to lead companies to engage in targeted poverty alleviation when they are in heavily polluting industries or face greater pressure from external investors.Finally,we find that active involvement in targeted poverty alleviation helps companies improve their market reputation and thus effectively manage public relations crises caused by negative media coverage.

EFFECTS OF MEDIA COVERAGE AND TEMPORARY IMMUNITY TO A STOCHASTIC SEIR EPIDEMIC MODEL

A type of SEIR epidemic model with media coverage and temporary immunity is investigated in this paper. The existence and uniqueness of the global positive solution with any positive initial value is proved. Under the condition R0s> 1, we prove that the disease is persistent in the mean for a long run. Furthermore, by constructing suitable Lyapunov functions, some sufficient conditions that guarantee the existence of stationary distribution are derived. We also obtain that, if the condition R0e< 1 is satisfied, then the disease is extinct with an exponential rate. As a consequence, some examples and numerical simulation are demonstrated to show the validity and feasibility of the theoretical results.

Coverage and Information Treatment of Zika in Ecuador:Analysis of News From National Newspapers El Universo and El Telégrafo

Zika is an infectious disease that emerged as an epidemic in Latin America in 2015 and arrived in Ecuador at the start of 2016.This research analyzes the coverage that two national Ecuadorian newspapers gave to this sanitary emergency.Journals El Telégrafo and El Universo,the first one of government domain and the other one of a private company,were chosen to be studied,and interviews with journalists who reported before,during and after the epidemic,were conducted.The results showed that:In most news articles,a single source is handled,preferably the official or institutional one;that the majority of articles were about the international situation rather than local or national information;that alarm content is privileged over the preventive;and finally that the earthquake that hit the Ecuadorian coast in April 2016 weakened the coverage of Zika,even though the epidemic was at its outbreak at the time in the country.There is a need for journalists to be trained to cover these types of emergencies in order to better inform the people and follow up diseases cycles in order to arrange their own news agenda and work more on solution approaches.

Business and financial information integration and voluntary management earnings forecasts

In this study,the impact of business and financial information integration(BFⅡ)on the voluntary management earnings forecasts(VMEFs)of listed firms in China between 2008 and 2018 is investigated.Drawing on litigation cost and ability signaling theories,we find that the adoption of BFⅡencourages top managers to disclose VMEFs.BFⅡfirms are identified through the textual analysis of management discussion and analysis(MD&A)reports,and the empirical results indicate that BFⅡfirms have a higher probability and frequency of issuing VMEFs than non-BFⅡfirms.The results remain robust after we identify causality by applying a propensity score matching and difference-in-differences(PSM-DID)test and use an alternate measure of BFⅡ.Further tests show that BFⅡfirms issue more accurate VMEFs and are able to issue them at an earlier stage.We also find that the positive relationship between BFⅡand VMEFs is weakened if the media expresses concern about the uncertainty of BFⅡadoption.