Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Kasuga-koen, Kasuga-shi, Fukuoka 816-8580, Japan.
Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Kasuga-koen, Kasuga-shi, Fukuoka 816-8580, Japan; Department of Mathematics, University of Dhaka, Dhaka 1000, Bangladesh.
J Theor Biol. 2021 Jul 7;520:110682. doi: 10.1016/j.jtbi.2021.110682. Epub 2021 Mar 18.
With the aid of the evolutionary vaccination game on a scale-free network, we design a new subsidy policy, named degree dependent subsidy, where cooperative agents get incentives according to their connectivity or degree. That is, agents, having a greater degree, receive a higher incentive, and vice versa. Here we presume that vaccinators are cooperative agents. The new scheme can be said to an intermediate policy between two previously studies policies, namely free ticket and flat discount policies. The former policy distributes free tickets to cooperative hub agents as a priority, whereas the latter dispenses a fixed discount to every cooperator. We compare the efficiency of each policy in terms of having a less infectious state with a minimum social cost. While investigating the performance of the three policies in terms of average social payoff-which takes into account the cost of vaccination as well as infection-the free ticket scheme is found to be the most appealing policies among the three when the budget for subsidy is quite low. The degree dependent subsidy policy outperforms others for a moderate budget size, while the flat discount policy requires a higher budget to effectively suppress the disease. We further estimate threshold levels of the subsidy budget for each policy beyond which subsidizing results in excessive use of vaccination. As a whole, concerning vaccination coverage and final epidemic size, the degree-dependent subsidy scheme outperforms the flat discount scheme, but is dominated by the free ticket policy.
在无标度网络上的进化疫苗接种博弈的帮助下，我们设计了一种新的补贴政策，称为度相关补贴，根据合作方的连接度或度数给予合作方激励。也就是说，度数较大的代理会得到更高的激励，反之亦然。在这里，我们假设接种者是合作方。与之前研究的两种政策（免费票政策和固定折扣政策）相比，新方案可以说是一种中间政策。前者优先向合作枢纽代理分配免费票，而后者则向每个合作者提供固定折扣。我们比较了每种政策在具有最小社会成本的较少传染性状态下的效率。在考虑到接种成本和感染成本的平均社会收益方面，免费票政策在补贴预算非常低的情况下是三种政策中最具吸引力的政策。度相关补贴政策在中等预算规模下表现优于其他政策，而固定折扣政策则需要更高的预算才能有效抑制疾病。我们进一步估计了每种政策的补贴预算阈值水平，超过该阈值，补贴就会导致过度使用疫苗接种。总的来说，在接种覆盖率和最终疫情规模方面，度相关补贴方案优于固定折扣方案，但被免费票方案所主导。
