Has the Digital Economy Changed the Urban Network Structure in China?—Based on the Analysis of China’s Top 500 New Economy Enterprises in 2020

The rapid development of the new generation of information technology makes digital enterprises and the digital economy important forces in promoting the sustainable growth of the world economy. Under the influence of the digital economy, the original urban network may undergo drastic changes. There have been studies that have arrived at conflicting conclusions. This paper primarily illustrates whether or not the digital economy has changed the urban network structure. China's digital economy is developing rapidly, becoming a new engine for the high-quality development of the Chinese economy. Therefore, this paper demonstrates the impact of China's digital economy on the urban network structure by using data from China's Top 500 New Economy Enterprises in 2020 and the headquarter–subsidiary ownership method. The results show that 1) China's urban network has changed significantly. Compared with APS enterprises and listed companies, the urban network of the digital economy has become more polarized, and Beijing has become the absolute control center. 2) Chinese cities have been reshuffled in the era of the digital economy. Beijing, Hangzhou, and Chengdu, with their industrial foundations in the digital economy, have performed better within the network. Simultaneously, some heavily industrialized cities, such as Wuhan, Shenyang, and Chongqing, have been declining due to the difficulties associated with transformation. 3) Although the digital economy has reshaped China's urban network structure to a certain extent, the original urban pattern still plays a dominant role in the new system. The network spatial pattern of dense east and sparse west still exists, and provincial capitals and subprovincial cities still play a more significant role in the network than ordinary cities. 4) Network diffusion is typically a hierarchical diffusion between core nodes. Geographical proximity has a low constraint on network diffusion, and subsidiaries expand outward through hierarchical diffusion.

The spatial diffusion of fertility decline in Egypt (1950–2006)

While the Egyptian fertility transition has been widely addressed in the literature, few researches have studied the spatial dimension of fertility. Using population census data, the aim of this study is to describe and measure the evolution of the geography of fertility on a subnational scale (qism/markaz), focusing on the period between 1960 and 2006. We assumed that the decline in fertility had spread spatially through Egypt, the spatial diffusion occurring through two traditional mechanisms: contagion and hierarchical diffusion. Our results confirm our hypotheses and highlight the importance of studying the spatial diffusion of the fertility transition. This study is unique for the Egyptian context given the long period and fine territorial scale considered. Our study constitutes an important addition to the existing group of studies on the spatial diffusion of fertility. Finally, it contributes to gaining further insight into a demographic dynamic which is fundamental for the future of Egypt.

Creative or Not? Hierarchical Diffusion Modeling of the Creative Evaluation Process

When producing creative ideas (i.e., ideas that are original and useful) two main processes occur: ideation, where people brainstorm ideas, and evaluation, where they decide if the ideas are creative or not. While much is known about the ideation phase, the cognitive processes involved in creativity evaluation are largely unclear. In this paper, we present a novel modeling approach for the evaluation phase of creativity. We apply the drift diffusion model (DDM) to the creative-or-not (CON)-task to study the cognitive basis of evaluation and to examine individual differences in the extent to which people take originality and utility into account when evaluating creative ideas. The CON-task is a timed decision-making task where participants indicate whether they find uses for certain objects creative or not (e.g., using a book as a buoy). The different use items vary on the two creativity dimensions ‘originality’ and ‘utility’. In two studies (n = 293, 17806 trials; n = 152, 9291 trials), we found that stimulus originality was strongly related to participants’ drift rate, whereas stimulus utility was only somewhat associated with the drift rate. However, participants differed substantially in the effects of originality and utility. Furthermore, the implicit weights assigned to originality and utility on the CON-task were aligned with self-reported importance ratings of originality and utility and associated with divergent thinking performance. Our findings underline the importance of communicating rating criteria in divergent thinking tasks such as the alternative uses task to ensure a fair assessment of creative ability.

The Vulnerability and Resilience of African Food Systems, Food Security, and Nutrition in the Context of the COVID-19 Pandemic

As the COVID-19 pandemic rages across the globe, ebbing and flowing from one region to the next, new infections and deaths continue to rise (Johns Hopkins 2020). Some of the first documented cases in Africa occurred in areas frequented by foreign tourists. Early on, the disease also circulated among Africa’s jet-setting political classes that had spent time in other regions of the world with higher infection rates. Since then, infections have taken off in the continent’s urban areas that are better connected globally via trade and travel. From there, it has spread to smaller cities, towns, and then to rural areas, a process known as hierarchical diffusion (Moseley 2020a). Unfortunately, there is another scourge that accompanies COVID-19, and that is a global hunger pandemic. In April 2020, the director of the World Food Programme warned that an additional 130 million people could be pushed to the brink of starvation by the end of 2020 because of the coronavirus. This comes on top of the 821 million people in the world who are already food insecure (Khorsandi 2020). Increasingly, scholars of food security, food systems, and poverty have come to realize that the hunger and malnutrition associated with COVID-19 may actually kill or debilitate more people than the disease itself, especially in regions of the world with weaker social safety nets (Fanzo 2020; HLPE 2020a, 2020b; UN 2020).

Hierarchical Diffusion Attention Network

A series of recent studies formulated the diffusion prediction problem as a sequence prediction task and proposed several sequential models based on recurrent neural networks. However, non-sequential properties exist in real diffusion cascades, which do not strictly follow the sequential assumptions of previous work. In this paper, we propose a hierarchical diffusion attention network (HiDAN), which adopts a non-sequential framework and two-level attention mechanisms, for diffusion prediction. At the user level, a dependency attention mechanism is proposed to dynamically capture historical user-to-user dependencies and extract the dependency-aware user information. At the cascade (i.e., sequence) level, a time-aware influence attention is designed to infer possible future user's dependencies on historical users by considering both inherent user importance and time decay effects. Significantly higher effectiveness and efficiency of HiDAN over state-of-the-art sequential models are demonstrated when evaluated on three real diffusion datasets. The further case studies illustrate that HiDAN can accurately capture diffusion dependencies.

Two metropolisation gradients in the European system of cities revealed by scaling laws

Urban systems share with other complex systems constraints on their dynamics that are revealed by pervasive structural features, among which scaling laws. Scaling laws are relationships between cities’ attributes and their size (here measured by their population). When the relationship is non proportional with exponents larger than 1, scaling laws indicate the relative concentration of some urban functions at the higher levels of urban hierarchies. Superlinear scaling thus reveals the metropolisation trends that are produced in the urban system, according to our evolutionary theory perspective, by the hierarchical diffusion of innovation waves. Considering the current urban changes linked with the globalisation processes as an ‘innovation’ that is likely to diffuse hierarchically in urban systems, we analyse the relationships between 25 indicators expressive of their position in globalisation processes and the size of European cities (356 largest functional urban areas of the 28 European Union member states plus Switzerland and Norway). When summarised in a single metropolisation factor, we expected to find a unique superlinear scaling relationship that would reveal the hierarchical structure of the unifying European system of cities. We instead identify two distinct metropolisation gradients for each of the Western and Eastern subsystem that we interpret according to the delayed globalisation process in the latter. This provides a demonstration of the usefulness of scaling laws for summarising stages in the process of hierarchical diffusion of innovation in systems of cities.

Unifying models of dialect spread and extinction using surface tension dynamics

We provide a unified mathematical explanation of two classical forms of spatial linguistic spread. The wave model describes the radiation of linguistic change outwards from a central focus. Changes can also jump between population centres in a process known as hierarchical diffusion . It has recently been proposed that the spatial evolution of dialects can be understood using surface tension at linguistic boundaries. Here we show that the inclusion of long-range interactions in the surface tension model generates both wave-like spread, and hierarchical diffusion, and that it is surface tension that is the dominant effect in deciding the stable distribution of dialect patterns. We generalize the model to allow population mixing which can induce shrinkage of linguistic domains, or destroy dialect regions from within.