International Trade and Income Inequality*

We propose a simple theory that shows a mechanism through which international trade entails wage and job polarization. We consider two countries in which individuals with different abilities work either as knowledge workers, who develop differentiated products, or as production workers, who engage in production. In equilibrium, ex ante symmetric firms attract knowledge workers with different abilities, and this creates firm heterogeneity in product quality. Market integration disproportionately benefits firms that produce high-quality products. This winner-take-all trend of product markets causes a war for talents, which exacerbates income inequality within the countries and leads to labor-market polarization.     

亚洲高速公路，许东盟一个美好未来

由大湄公河次流域国家酝酿、亚洲发展银行投资兴建的亚洲高速公路虽然还未竣工，已经证明了其巨大的经济效益，并在很大程度上改变着这个区域。[编者按]     

越中关系合作发展15年

2006年是越南-中国关系以及东盟-中国关系的重要一年。东盟与中国纪念建立对话关系15周年（1991-2006）的同时，越中关系自1991年正常化以来也刚满15周年。15年虽然在一个民族的历史中不算是很长，但也足以让越中两国在双方和多方的框架内为共同合作发展目标奠定了牢固的基础。我们在这里可以回顾过去的成就和经验，共同面向未来，为两个国家以及本区域和全世界的和平、稳定和发展而奋斗。     

Valuing cultural heritage in developing countries: comparing and pooling contingent valuation and choice modelling estimates

A substantial part of the United Nation’s World Heritage Sites (WHSs) can be found in developing countries, but many of them are in a bad state. Thus, there is a need to document the social benefits of these global goods in order to justify the costs of restoration and preservation programmes (RPPs). This study adds to the scarce literature on economic benefits of WHSs in developing countries, and reduces the need to perform very uncertain benefit transfers from European or US valuation studies. We apply Contingent Valuation (CV) and Choice Modelling (CM) to estimate the social benefits of RPPs for the My Son world cultural heritage site in Vietnam; both to foreign visitors and the local residents. We then compare the estimates from the CV and CM methods, and pool the results from the two methods. The results show that both CV and CM are suited to estimating the economic benefits of preserving cultural heritage of My Son. The two methods produce very similar results, which can be interpreted as a test of convergence validity. The pooling results give evidence to show that the CV and CM models have the same underlying preference structures. Thus, these valuation models can be successfully used in cost-benefit analyses to assess the benefits to cultural heritage of measures to reduce air pollution, soil erosion, climate change and other causes to deterioration of cultural heritage sites.

A general framework for measuring VAT compliance rates

Summary measures of Value Added Tax (VAT) compliance rates are valuable for identifying problem areas in VAT implementation. They are also essential for meaningful crosscountry and crosstime comparisons of VAT compliance. We present a comprehensive and general framework for calculating VAT compliance rates at both the economy wide and detailed sectoral levels. Unlike existing measures of VAT compliance, our framework isolates a compliance measure from the effects on VAT receipts of detailed features of VAT systems as actually implemented by tax authorities. These features include multiple VAT rates, exemptions, registration rates, refund limitations, informal activity, taxation of domestic nonresidents and undeclared imports. We implement our comprehensive VAT compliance measure for Vietnam, a country with a complex VAT system. Our estimate of Vietnam's VAT compliance rate is about 13 percentage points higher than that calculated by the most popular measure of compliance, Collection Efficiency (CE). Our method facilitates decomposition of the difference between CE and our VAT compliance measure into individual contributions by the statutory and structural features of Vietnam's VAT regime.     

Lump‐Sum versus Pay‐As‐You‐Go: The Moderating Effect of Contract Types on the Optimal Logistics Decisions

When outsourcing their logistics operations to transportation companies, manufacturers/retailers need to design a contract, under which payment can be made either in a lump sum or over time (i.e., per each delivery). This paper investigates how the payment method (i.e., type of contracts) impacts the transporter's delivery schedule by developing an analytical model based on the optimal control and game theories. Our findings show that the transporter's delivery schedule depends on the method of payment and the overall cost of hiring a transporter varies with the types of contracts. We provide theoretical explanations to these findings along with managerial implications. Copyright © 2016 John Wiley & Sons, Ltd.     

Adaptive algorithms for maximizing overall stock return

Deciding which stocks to purchase and how to optimally allocate the total investment among them is a nontrivial task for every investor. In this article, we propose two adaptive techniques that would provide an optimal allocation maximizing the return over the investment period. The first approach is the adaptive power method (PM) which is a modification of the proper orthogonal decomposition method. The adaptive PM uses only the currently available information to compute the optimal allocations, yet its long-term solution approaches the dominant eigen solution, even though that solution would require having a priori knowledge of all stocks’ performance. The second approach is derived from the well-known Least Mean Square (LMS) method, where the optimal allocation can be computed by adaptively steering the overall return toward a desired value. The experimental results have indicated promising gains even when the general market trend is downward.     

Diversification strategies and firm performance in Vietnam

This paper is based upon the assumption that a firm's profitability is determined by its degree of diversification which is, in turn, strongly related to the antecedent decision to carry out diversification activities. This calls for an empirical approach that permits the joint analysis of the three interrelated and consecutive stages of the overall diversification process: diversification decision, degree of diversification and outcome of diversification. We apply parametric and semi‐parametric approaches to control for sample selection and the endogeneity of the diversification decision in both static and dynamic models. For the analysis, we use the census dataset on the whole firm population in Vietnam, as a representative of transition countries. After controlling for industry fixed‐effects, the empirical evidence from the firm‐level data shows that diversification has a curvilinear effect on profitability: it improves firms’ profit up to a point, after which a further increase in diversification is associated with declining performance. This implies that firms should consider optimal levels of product diversification when they expand their product offerings beyond their core business. Other noteworthy findings include the following: (i) the factors that stimulate firms to diversify do not necessarily encourage them to extend their diversification strategy; (ii) firms that are endowed with highly technological resources and innovation investment are likely to successfully exploit diversification as an engine of growth; and (iii) while industry performance does not have a strong influence on the profitability of firms, it impacts their diversification decision as well as the degree of diversification.     

Modelling value-added tax in the presence of multi-production and differentiated exemptions

We develop a framework for economy-wide modelling of value-added tax systems. Our framework models a number of complexities of VAT systems as implemented by tax agencies. In particular, we model multiple rates, multiple exemptions, multiple degrees of refundability across commodity users, and multi-product enterprises. We use our framework to model what is arguably South East Asia's most complex VAT system: that of Vietnam. We analyse the macroeconomic, industrial and distributional effects of simplifying Vietnam's complex VAT system. We simplify the system via a budget-neutral movement to one rate and removal of discretionary exemptions. This generates an aggregate welfare gain, but adverse distributional effects. Adverse distributional effects can be greatly ameliorated, at small cost to the aggregate welfare gain, via exclusion of paddy and rice from the VAT simplification program.