Network ties and export propensity of Vietnamese small and medium enterprises

This paper investigates the impacts of different network ties on export propensity of Vietnamese small and medium enterprises (SMEs) in the manufacturing sector. Using data from a survey of over 2,600 manufacturing SMEs in 2015, we found that social networks contribute positively to the export propensity of SMEs, while the size of business networks negatively associates with the likelihood of export. However, bank networks and political networks are not significant for the propensity to export of Vietnamese SMEs. We discuss the results in detail and offer recommendations for SME owners, managers and policy makers.     

Time series momentum and moving average trading rules

We compare and contrast time series momentum (TSMOM) and moving average (MA) trading rules so as to better understand the sources of their profitability. These rules are closely related; however, there are important differences. TSMOM signals occur at points that coincide with a MA direction change, whereas MA buy (sell) signals only require price to move above (below) a MA. Our empirical results show MA rules frequently give earlier signals leading to meaningful return gains. Both rules perform best outside of large stock series which may explain the puzzle of their popularity with investors, yet lack of supportive evidence in academic studies.     

The Role of Financial Ratios in the Variance of Stock Trading Volume in Emerging Stock Markets

The study used quarterly panel data of 6 years from 2010 to 2015 of all companies listed on both Vietnamese stock markets including the Ho Chi Minh City Stock Exchange and Ha Noi Stock Exchange, and on three leading industries consisting of insurance-banking, foodstuff, and real estate to explore the relationship among four key financial ratios and stock trading volume. Two models, fixed effects model (FEM) and random effects model (REM), with robust standard errors, were applied for this study. The key findings showed that earnings before tax on sales, debt on owner’s equity, and owner’s equity on total assets significantly influenced trading volume.     

Subnational home market bias in Vietnam: Evidence from enterprise‐level data

This paper contributes to the home (market) bias literature where administrative or political borders limit trade across borders. Home bias is well documented at the national and subnational level. To sort out macro (e.g., location characteristics) and micro (e.g., enterprise characteristics) factors behind home bias, we use small and medium‐sized enterprise (SME) data from Vietnam. Using the fractional multinomial logit model, we find that the proportion of SME sales outside of their home markets is positively associated with enterprise size, age, number of business association memberships and the distance of SMEs' most important supplier. In contrast, the proportion of SME sales to neighbouring provinces is negatively associated with the share of SME production for final consumption. Besides enterprise‐level frictions, market characteristics matter too. The proportion of SME sales to customers in their home markets is negatively associated with home or neighbouring provinces' governance quality, while the proportion of sales to customers in neighbouring provinces is positively associated with these areas' governance quality. These suggest that good governance frees SME resources for use in selling to less familiar markets.     

Robust Markowitz mean‐variance portfolio selection under ambiguous covariance matrix

This paper studies a robust continuous‐time Markowitz portfolio selection problem where the model uncertainty affects the covariance matrix of multiple risky assets. This problem is formulated into a min–max mean‐variance problem over a set of nondominated probability measures that is solved by a McKean–Vlasov dynamic programming approach, which allows us to characterize the solution in terms of a Bellman–Isaacs equation in the Wasserstein space of probability measures. We provide explicit solutions for the optimal robust portfolio strategies and illustrate our results in the case of uncertain volatilities and ambiguous correlation between two risky assets. We then derive the robust efficient frontier in closed form, and obtain a lower bound for the Sharpe ratio of any robust efficient portfolio strategy. Finally, we compare the performance of Sharpe ratios for a robust investor and for an investor with a misspecified model.     

Correction to: Are two brands better than one? Investigating the effects of co-branding in advertising on audience memory

Marketing Letters - The article Are two brands better than one? Investigating the effects of co-branding in advertising on audience memory, written by Cathy Nguyen, Jenni Romaniuk, Margaret...     

A Systematic Review on the Effects of Personalized Price Promotions for Food Products

Recent decades have witnessed the increasing adoption of personalized price promotion (PPP) at grocery stores. Despite the growing body of research debating whether PPP is more effective than untargeted price promotions, there is no literature synthesizing the relevant evidence on food products. Therefore, we conduct a systematic review to examine empirical findings on the effects of PPP targeting food products. Outcomes of 12 identified studies demonstrate larger sales and profit boosting effects of PPP than its non-personalized counterparts. Meanwhile, the results on how this approach influences consumer behavior are mixed. The effectiveness of PPP varies among different targeting strategies (e.g. reward or cross-selling) and information collection methods (e.g. using within- or across-chain data). The findings of this review have important managerial implications for the future evaluation and application of PPP as well as imply potential directions of further research on this topic.