Ronald Jones's duality analysis as a foundation for applied general‐equilibrium modeling

Ronald Jones made seminal contributions to general‐equilibrium theory, moving away from an emphasis on the existence of equilibrium to algebraic formulations which enabled us to characterize key relationships between parameters and variables, such as that between tariffs and domestic factor prices and welfare. But the analysis remained limited in value for policy evaluation: the analysis was local, it provided only qualitative results, it was limited to very small models, and strictly interior solutions had to be assumed. The contribution of this paper is largely pedagogic and methodological. I show how the tools and approach pioneered by Jones can be generalized via the use of duality, complementarity and the Karush–Kuhn–Tucker theorem into a global, quantitative analysis of large changes in high‐dimensional models which also allows for regime changes and corner solutions. I then show how the resulting nonlinear complementarity problem directly translates into a numerical model using the General Algebraic Modeling System (GAMS).     

General existence of competitive equilibrium in the growth model with an endogenous labor–leisure choice

We prove the existence of competitive equilibrium in the canonical optimal growth model with elastic labor supply under general conditions. In this model, strong conditions to rule out corner solutions are often not well justified. We show using a separation argument that there exist Lagrange multipliers that can be viewed as a system of competitive prices. Neither Inada conditions, nor strict concavity, nor homogeneity, nor differentiability are required for existence of a competitive equilibrium. Thus, we cover important specifications used in the macroeconomics literature for which existence of a competitive equilibrium is not well understood. We give examples to illustrate the violation of the conditions used in earlier existence results but where a competitive equilibrium can be shown to exist following the approach in this paper.     

Internal habits formation and optimality

In a very influential model with internal habits, Carroll et al., (2017, 2000), establish that an increase in economic growth may cause a positive change in savings. The optimality of this result, and of many other contributions using a similar framework, has been questioned by some authors who have observed that the parametrization used in these models always implies a utility function not jointly concave in consumption and habits. In this paper, we revisit the optimality issue and, using advanced techniques in Dynamic Programming, we answer the following long-standing open questions: (i) Is the solution found in Carroll et al., (2017, 2000) optimal? (ii) Is it also unique or do other optimal solutions exist?     

The time‐varying performance of UK analyst recommendation revisions: Do market conditions matter?

This study examines the time‐varying performance of investment strategies following analyst recommendation revisions in the UK stock market, with specific emphasis on the impact of changing market conditions. We find a negative relationship between the recommendation performance and market conditions as measured in terms of past market return and market volatility. In particular, the upgrade (downgrade) portfolio generates significantly positive (negative) net abnormal returns in bad market conditions (e.g., the dot‐com bubble burst in 2000 and the credit crisis in 2007), but not in other periods of time. Moreover, our non‐temporal threshold regression analysis shows that the reported negative relationship disappears when market conditions become better, i.e., when the past market return (market volatility) is higher (lower) than a certain level, indicating the importance of taking non‐linearity into account in the long sample period as examined in this study. Our time‐series bootstrap simulations further confirm that the superior recommendation performance in bad market conditions is not due to random chance; analysts have certain skills in making valuable up/downward revisions in bad markets.     

The reverse tragedy of the commons: an exploratory account of incentives for under-exploitation in an open innovation environment*

This paper presents an empirical account of a phenomenon that we refer to as the ‘reverse tragedy of the commons’ in open innovation. The name signifies the ‘under-exploitation’ of intellectual property (IP) under weak appropriability. The name is this graphic because the tragedy is costly, and can also render IP effectively worthless and block innovation in the short to medium term. We propose that the tragedy is borne out of the interaction between enterprise characteristics, a competitive setting and the framework that is set by the policy intervention. This finding is pertinent to policy-makers with regard to the design of research, development and innovation instruments, as well as managers who must determine how to implement open practices in innovation.     

Doorsteps Toward Political and Economic Openness: Testing the North-Wallis-Weingast Transition Framework

In this paper, we test the theoretical framework developed by North, Wallis, and Weingast (2009), who posit that limited-access societies need to meet three doorstep conditions before they can transit into open-access societies: (1) establishment of rule of law among elites, (2) adoption of perpetually existing organizations, and (3) political control of the military. We identify indicators reflecting these doorsteps and econometrically test their relationships with specific political and economic variables. We broadly confirm the logic behind the doorsteps as necessary conditions in the transition to open-access societies. The doorsteps influence economic and political processes, as well as each other, with varying intensities.     

团队跨边界活动对团队有效性的影响作用研究

通过文献综述,得出了团队跨边界活动对团队有效性有着倒U型的影响作用这一结论。同时,在团队学习理论和社会网络理论的基础上,对上述作用的内部机制进行研究探索,并从团队和个体两个层面分析相关的影响因素。最后,从企业管理实践的角度出发,基于研究结果提出几点思考和意见。     

有限责任公司股权转让若干法律问题探讨

有限责任公司股权转让包括内部转让和外部转让。股东之间转让股权一般是自由的,但受公司章程的限制。股东向公司以外第三人转让股权关系到其他股东权利的保护,所以在实务中,应全面理解把握法律规定的同意条件和优先购买权两个实质性条件。     

产品生命周期的研究

产品生命周期是指一代产品进入市场后需求存续变化的周期,而不是指需求量、销量波动变化的周期。我们应当研究细分市场的产品生命周期,根据市场某种特性质变的界面来划分产品生命周期的阶段,才更具有营销意义。现行流行的划分产品周期阶段的四种方法。缺乏理论依据,在应用中有较大的随意性。为此,提出了综合判断法,根据多个判据的组合,定位了产品生命周期阶段之间的界面,并提出了对应的营销策略。