Explosive enterprises’ immoral behaviors in the online shopping market are widespread and have not been effectively solved. Especially in developing countries, there is a direct relationship between massive immoral behaviors and the inefficiency of government supervision. Using an evolutionary game, this paper finds that immoral behavior is more likely to spread in online markets than in traditional markets. Only when government supervision and punishment are large enough and government’s punishment for the illegal enterprise exceeds extra supervision costs that government pays, explosive immoral behaviors can be curbed. Additionally, consumer support is an essential factor in improving the efficiency of government supervision. This study sorts out the interactions between e‐commerce market participants and the government, obtains a path to achieve efficient government regulation, and offers management insights. The findings can serve as a reference for ensuring order in the emerging online shopping market and can also provide theoretical references for future related research.

Purpose: Considering the network externalities of online selling, this paper builds three different online direct selling models: manufacturer direct selling (MN model), network platform direct selling (NN model) and retailer direct selling (RN model). The optimal advertising and pricing decision and corporate profits under each selling model are investigated.Design/methodology/approach: Combining the characteristics of online direct selling, this paper formulates direct selling models that are dominated by different companies as Stackelberg game models. Numerical analyses are carried out, along with the comparison of the equilibrium solutions for each model.Findings: The authors' research shows that increasing network externalities is conducive to the development of enterprises. The network platform's profit is the lowest in the RN model and the highest in the NN one. The comparison of manufacturers' profits between the MN model and the NN model primarily depends on consumers' sensitivities for sales price and advertising promotion level. The manufacturer does not benefit from the RN model due to the lowest efficiency.Originality/value: Coupled with three different online direct selling models and detailed analyses of the optimal solutions, this study has enriched the theoretical foundation of online direct selling. Moreover, this study extends the research of network externalities to the field of e-commerce, revealing the network externalities' influence on the decision-making of the e-supply chain.

This study examines the impact of subsidy phase-out policies on firm-level research and development (R&D) investment in the new energy sector. A sequential game-theoretic model is developed to analyze strategic interactions between government and firms, and its implications are empirically tested using a propensity score matching difference-in-differences approach based on Chinese listed manufacturing firms from 2016 to 2021. The results show that subsidy phase-out policies significantly reduce firms’ R&D investment. This negative effect operates primarily by deteriorating firms’ operating performance. The impact is more pronounced for non–state-owned firms, high-growth firms, and firms located in central regions. The theoretical analysis further reveals that subsidy efficiency, market expansion effects, and firms’ subsidy capture rates exhibit diminishing marginal returns. Excessive subsidies also redirect fiscal resources toward consumers with weaker low-carbon preferences. Based on these findings, this study proposes an integrated subsidy phase-out mechanism incorporating the phase-out rate, critical trigger thresholds, and the phase-out period. The mechanism is designed to prevent market contraction, ensure that policy exit is synchronized with the growth of endogenous market forces, and ultimately facilitate the transition of the new energy industry from policy-driven to market-driven development.