Government expenditure and economic growth: A heterogeneous-agents approach

This study examines the relationship between productive government expenditures and economic growth. An R&D-based model of endogenous growth is used, in which agents have heterogeneous entrepreneurial abilities. We show that if the number of high-ability entrepreneurs is non-negligible, then the relationship between the government expenditure/GDP ratio and the economic growth rate is depicted by an inverted U-shaped curve with a flat top. The flat top of the curve indicates that changes in the size of the government expenditures have a limited impact on growth. We calibrate the model using U.S. data and empirically confirm our theoretical predictions. The theoretical and numerical results suggest that the debate on the relationship between the size of the government and economic growth may be off the mark unless the size of the government is extremely large or small.     

Social effects of topic propagation on Weibo

Weibo, China’s largest microblogging platform, has become one of the key information-sharing platforms in modern society. This study examines topic propagation in relation to microblogging from the perspective of the “peer effect.” Using data of hot topics from Weibo, we analyze how the social effect and propagation pathway influence the topic propagation process. We propose a spatial and temporal heterogeneity diffusion model that includes endogenous and exogenous social effects and is based on but different from the Bass diffusion model. We find that most propagation pathways end after a single level of propagation. The endogenous social effect in microblogs primarily influences the inflow of topics. Such endogenous social effect, combined with the multiplier effect, motivates most users to share a microblog topic in a short period of time. The exogenous social effect primarily influences the outflow of topics, and therefore, the microblog topics of a small number of popular users’ account for most of the share volume. Our results are robust to potential serial correlation, reflection problem, and potential self-selection due to user status.The findings reveal that group characteristics affect individuals’ behaviors and choices in relation to the topic propagation process on microblogging platforms. The use of a spatial and temporal heterogeneity diffusion model and the robustness of the analysis process provide new information for scholars in this field.     

Socio-political instability and growth dynamics

We develop an overlapping generations (OLG) monetary endogenous growth model characterized by socio-political instability, with the latter being specified as a fraction of output lost due to strikes, riots and protests. We show that growth dynamics arise in this model when socio-political instability is a function of inflation. In particular, two distinct growth dynamics emerge, one convergent and the other divergent contingent on the strength of the response of socio-political instability to inflation. Since our theoretical results hinge on socio-political instability being a function of inflation, we test the prediction that inflation affects socio-political instability positively by using a panel of 156 countries for the 1980–2012 period, and allowing for country and time fixed effects. The results indicate that inflation relates positively with socio-political instability. Policy makers should be cognisant that it is crucial to maintain long-run price stability, as failure to do so may result in high inflation emanating from excessive money supply growth, leading to high (er) socio-political instability, and ultimately, the economy being on a divergent balanced growth path.     

A political economy approach to endogenous industrial policies

This paper uses a political economy perspective to study the endogenous formation of economic policies and its interplay with political institutions. This paper provides a novel view that both the institutions and economic development status are essential factors in endogenously determining economic policies. The model aims to explain both the differences in the degree of adopting industrial policies as well as the differences in the types of industrial policies being implemented. Using a concise framework with two country-specific characteristics, the baseline model can capture three main types of industrial policy platforms of interest. In a country where voters’ political awareness is positively skewed and press freedom is relatively low, pro-heavy industry policies would be present most of the time; South Korea is representative of this type of countries. In a country where voters’ political awareness is positively skewed and press freedom is relatively high, there is usually an active industrial policy, though the target of the policy changes over time. Specifically, the policy is favoring the industry of which the industry-specific TFP is relatively high; Japan is representative of this type of countries. In a country where voters’ political awareness is negatively skewed and press freedom is relatively high, there is usually no active industrial policy; the U.S. is representative of this type of countries.     

乡村振兴背景下蔬菜价格波动因素分析及预测

近年来在农产品批发市场上，蔬菜价格波动幅度较大。将影响蔬菜价格的因素划分为供给、需求、流通、气候和其他5大类，构建Lasso-SVM最优组合预测模型预测蔬菜价格。研究结果表明：人民币汇率、新冠感染者月均增加人数、气温平均值、农业生产价格资料指数、农产品生产价格指数、劳动日工价、物质与服务费用、用工成本和蔬菜播种面积对蔬菜价格影响较大；对比多种预测模型发现，Lasso-SVM模型组合预测蔬菜价格准确度高、性能稳定。