This paper concerns with modeling and design of an algorithm for the portfolio selection problems with fixed transaction costs and minimum transaction lots. A mean-variance model for the portfolio selection problem is...This paper concerns with modeling and design of an algorithm for the portfolio selection problems with fixed transaction costs and minimum transaction lots. A mean-variance model for the portfolio selection problem is proposed, and the model is formulated as a non-smooth and nonlinear integer programming problem with multiple objective functions. As it has been proven that finding a feasible solution to the problem only is already NP-hard, based on NSGA-II and genetic algorithm for numerical optimization of constrained problems (Genocop), a multi-objective genetic algorithm (MOGA) is designed to solve the model. Its features comprise integer encoding and corresponding operators, and special treatment of constraints conditions. It is illustrated via a numerical example that the genetic algorithm can efficiently solve portfolio selection models proposed in this paper. This approach offers promise for the portfolio problems in practice.展开更多
China＇s economic growth miracle despite complicated administrative approval formalities prompted us to raise the following question： ls it true that reforming administrative approval will promote economic growth？ B...China＇s economic growth miracle despite complicated administrative approval formalities prompted us to raise the following question： ls it true that reforming administrative approval will promote economic growth？ Based on our analysis on market entry, we discovered that reforming administrative approval will spur economic growth by reducing transaction cost for firms. Administrative approval may suppress social cost and propel China＇s economic growth; China＇s gradualist approval reforms may indeed propel economic growth by reducing transaction cost for firms. With the data of prefecture-level cities during 2000-2013 and data of companies listed on the SME board during 2010-2014, we tested the effects of approval reforms on economic growth and on transaction cost, and employed instrumental variable and PSM for the treatment of the endogeneity problem - all these tests led to robust and consistent results. Moreover, we discovered that difference in government policy implementation in the approval process is the root cause of corruption and rent seeking.展开更多
文摘This paper concerns with modeling and design of an algorithm for the portfolio selection problems with fixed transaction costs and minimum transaction lots. A mean-variance model for the portfolio selection problem is proposed, and the model is formulated as a non-smooth and nonlinear integer programming problem with multiple objective functions. As it has been proven that finding a feasible solution to the problem only is already NP-hard, based on NSGA-II and genetic algorithm for numerical optimization of constrained problems (Genocop), a multi-objective genetic algorithm (MOGA) is designed to solve the model. Its features comprise integer encoding and corresponding operators, and special treatment of constraints conditions. It is illustrated via a numerical example that the genetic algorithm can efficiently solve portfolio selection models proposed in this paper. This approach offers promise for the portfolio problems in practice.
文摘China＇s economic growth miracle despite complicated administrative approval formalities prompted us to raise the following question： ls it true that reforming administrative approval will promote economic growth？ Based on our analysis on market entry, we discovered that reforming administrative approval will spur economic growth by reducing transaction cost for firms. Administrative approval may suppress social cost and propel China＇s economic growth; China＇s gradualist approval reforms may indeed propel economic growth by reducing transaction cost for firms. With the data of prefecture-level cities during 2000-2013 and data of companies listed on the SME board during 2010-2014, we tested the effects of approval reforms on economic growth and on transaction cost, and employed instrumental variable and PSM for the treatment of the endogeneity problem - all these tests led to robust and consistent results. Moreover, we discovered that difference in government policy implementation in the approval process is the root cause of corruption and rent seeking.
