A REVISED GEOMETRY OF MEAN-VARIANCE EFFICIENT PORTFOLIOS

A revised definition of efficiency compares portfolios with different net worths. One axiom rules out instantaneous riskless gains, the other asserts that it costs money to buy good portfolios. Unlimited short sales are allowed. Portfolios which cannot be improved at any price are called absolutely efficient. The geometry of the mean-standard deviation frontiers is governed by three “efficient set constants”. A few results regarding efficient portfolios must be modified, and a new version of the security line equation is proposed. Explicit formulas are given: no need to use different formulas for singular or non-singular covariance matrix.     

Local integration and co‐evolution of internationalizing Chinese firms

This study investigates the integration of internationalizing Chinese firms into local host markets. We explore the market‐driven investment of a new wave of Chinese private and local state‐owned firms in Australia since 2012, which has replaced the initial large‐scale investment in resources by central state‐owned enterprises. Using an in‐depth analysis of nine Chinese firms operating in various sectors of the Australian market, we argue that market integration, adaptation, and bilateral institution‐building through co‐evolution and empowerment of local subsidiaries of Chinese multinational enterprises results in entrepreneurial autonomy and characterizes a new generation of Chinese investors. We propose that Chinese multinational subsidiaries have transferred domestic practices to the Australian market and have reconfigured domestic and host market resources to gain a competitive advantage in their original investment industry and new industries. Our study advances middle‐range theory building and provides a practical understanding of the strengths and weaknesses of Chinese investors, their potential to disrupt local markets, and their responsiveness to market‐oriented institutional guidance. The results of this study suggest that the bilateral institution‐building and resource reconfiguration capabilities of Chinese enterprises can be transferred to other developed and developing markets, including Belt and Road Initiative countries.     

Experience with a simulator for training ammonia plant operators

A computer-based simulator was used for training operators prior to the start-up of a new fertilizer complex which includes a 1,350-MTPD ammonia plant, two 1,100-MTPD urea plants, and a steam and power generation plant with two 18-MW gas turbines. The simulator offered many benefits, which can be used for continued education of operators and engineering studies.     

“Panelizing” Repeated Cross Sections

This paper considers the implementation of a non-stationary, heterogeneous Markov model for the analysis of binary dependent variables in a time series of repeated cross-sectional (RCS) surveys. The model offers the opportunity to estimate entry and exit transition probabilities and to examine the effects of time-constant and time-varying covariates on the hazards. We show how maximum likelihood estimates of the parameters can be obtained by Fishers method-of-scoring and how to estimate both fixed and time-varying covariate effects. The model is exemplified with an analysis of the labor force participation decision of Dutch and West German women using ISSP (and other) data from 10 annual Dutch surveys conducted between 1987 and 1996 and 7 annual West German surveys conducted between 1988 and 1994. Some open problems concerning the application of the model are discussed.     

Investigating Treatment Effects of Participating Jointly in SNAP and WIC when the Treatment Is Validated Only for SNAP

The U.S. Department of Agriculture operates several food assistance programs aimed at alleviating food insecurity. We study whether participation in both participation in both SNAP and WIC alleviates food insecurity compared with participation in SNAP alone. We bound underlying causal effects by applying nonparametric treatment effect methods that allow for endogenous selection and underreported program participation when validation data are available for one program (treatment) but not the other. We estimate average treatment effects using data from the National Household Food Acquisition and Purchase Survey (FoodAPS). FoodAPS includes administrative data to validate SNAP participation. Information on local food prices allows us to construct a food expenditure‐based monotone instrumental variable that does not require a typical instrumental variable exclusion restriction. Under relatively weak monotonicity assumptions, we identify that the impact of participating in both programs relative to SNAP alone is strictly positive, suggesting that the programs are nonredundant. This evidence can support improved design and targeting of food programs.     

Experience matters: The role of academic scientist mobility for industrial innovation

Research Summary: A learning‐by‐hiring approach is used to scrutinize scientists' mobility in relation to the recruiting firms' subsequent innovation output. Our starting point is that among firm hires, individuals with university research experience—hired from universities or firms—can be particularly valuable. However, conflicting institutional logics between academia and industry makes working with academic scientists challenging at times for firms. We suggest two solutions to this difficulty: hiring “ambidextrous” individuals with a mix of experience of university research and working for a technologically advanced firm, and a strong organizational research culture in the recruiting firm reflected by the presence of a scientist on the top management team. We track the mobility of R&D workers empirically using patent and linked employer‐employee data. Managerial Summary: An important way to make organizations more innovative is hiring individual researchers with the right types of skills and experience. We show that individuals with university research experience beyond their final degree are particularly likely to help boost firm‐level innovation output after hiring compared to R&D workers with other types of skills and experience. However, to obtain good returns to innovation from hiring such individuals, firms need a university research–friendly organizational culture when hiring individuals with university research experience, from either firms or academia.