Dynamic lot sizing problem with continuous-time Markovian production cost

This paper develops a polynomial algorithm for obtaining dynamic economic lot sizes in a single product multiperiod production system with the objective of minimizing total production and inventory costs over T periods. It is assumed that production costs are linear, inventory costs are concave, setup costs are zero and backlogging is not permitted in all periods. Moreover, the unit production cost is a stochastic variable, which is evolved according to a continuous-time Markov process over the planning horizon. The model is formulated as a stochastic dynamic programming (DP) optimization with the state variable being unit production cost. Then, it is solved using the backward dynamic programming approach. To justify the application of the proposed model, two practical cases are presented.     

Interpoint Distance Test of Homogeneity for Multivariate Mixture Models

Finite mixtures offer a rich class of distributions for modelling of a variety of random phenomena in numerous fields of study. Using the sample interpoint distances (IPDs), we propose the IPD‐test statistic for testing the hypothesis of homogeneity of mixture of multivariate power series distribution or multivariate normal distribution. We derive the distribution of the IPDs that are drawn from a finite mixture of the multivariate power series distribution and multivariate normal distribution. Based on the empirical distribution of the IPDs, we construct a bootstrap test of homogeneity for other multivariate finite mixture models. The IPD test is applied to mixture models for matrix‐valued distributions and a test of homogeneity for Wishart mixture is presented. Numerical comparisons show that IPD test has accurate type I errors and is more powerful in most multivariate cases than the expectation–maximization (EM) test and modified likelihood ratio test.     

Minorías étnicas foráneas y determinación salarial en China

Si bien algunos estudios observan que las minorías étnicas urbanas en China perciben salarios más bajos que la mayoría han, otros no constatan la existencia de esa brecha. Para resolver esta contradicción, los autores proponen desglosar las experiencias laborales por grupo étnico minoritario. El análisis de las minorías étnicas sobre un amplio conjunto de datos indica que las «minorías foráneas», como los tibetanos y los grupos túrquicos, sufren una penalización salarial significativa cuando se controlan las covariables, pero no ocurre lo mismo con la totalidad de las minorías. Estas conclusiones son robustas en varias especificaciones y tienen importantes implicaciones teóricas y en materia de políticas.     

A measure of regional influence with the analytic network process

The metropolitan region is commonly defined by a socio-spatial network of urban nodes that are linked in territory and function. Such a network is differentiated by size and dominance of the linked nodes, characterized by physical or virtual flows of a wide-ranging variety. The analytic network process (ANP) is a multi-criteria analytic method that measures the influence or dominance of the nodes in a network with feedback. We illustrate how ANP determines county rank as a measure of influence in a metropolitan statistical area (MSA) defined by its interrelated socio-economic and spatial elements qualitatively and quantitatively. We compare the ANP results to similar measures of regional influence in the literature.     

Entrepreneurship: Cause and Consequence of Financial Optimism

Extant evidence that the self‐employed overestimate their returns by a greater margin than employees is consistent with two mutually inclusive possibilities. Self‐employment may foster optimism or intrinsic optimists may be drawn to self‐employment. Previous research is generally unable to disentangle these effects because of reliance on cross‐sectional data. Using longitudinal data, this paper finds that employees who will be self‐employed in the future overestimate their short‐term financial wellbeing by more than those who never become self‐employed. Optimism is higher still when self‐employed. These results suggest that the greater optimism of the self‐employed reflects both psychological disposition and environmental factors. By providing greater scope for optimism, self‐employment entices the intrinsically optimistic.     

UNIFORM TECHNICAL PROGRESS: CAN IT BE HARMFUL?

Abstract.  In a model incorporating trade in final goods, intermediate goods and capital, we show how 'uniform' technical progress across sectors can lead to immiserization. The condition for immiserizing technical progress crucially depends on the pattern of specialization. Our results tend to hold in a more general specification of the basic structure.     

Exchange Rate Asymmetry and Flexible Exchange Rates under Inflation Targeting Regimes: Evidence from Four East and Southeast Asian Countries

While many have underscored the role of a flexible exchange rate policy under an inflation targeting (IT) regime, very few studies have examined what actually happens to exchange rate policy once the emerging market announces that it will adopt inflation targeting. The central contention of this paper is that while the adoption of an inflation targeting (IT) policy may lead to more flexible exchange rate movements, for various reasons it is possible that the degree of flexibility will be significantly higher on one side of the market. In this study, we demonstrate that four Asian economies—namely, Indonesia, Korea, the Philippines and Thailand—whom were among the first group of emerging markets to embrace the inflation targeting framework of monetary policy, tend to adopt a form of asymmetrical exchange rate behavior, wherein appreciation pressures are restrained more substantially than depreciation pressures.     

Impact of Financial Development on the Environmental Quality in Iran

In recent decades, undesirable environmental changes, such as global warming and greenhouse gases emission, have raised worldwide concerns. In order to achieve higher growth rate, environmental problems emerged from economic activities have turned into a controversial issue. The aim of this study is to investigate the effect of financial development on environmental quality in Iran. For this purpose, the statistical data over the period from 1970 to 2011 were used. Also by using the Auto Regression Model Distributed Lag （ARDL）, short-term and long-term relationships among the variables of model were estimated and analyzed. The results show that financial development accelerates the degradation of the environment; however, the increase in trade openness reduces the damage to environment in Iran. Error correction coefficient shows that in each period, 53% of imbalances would be justified and will approach their long-run procedure. Structural stability tests show that the estimated coefficients were stable over the period.     

Natural resource rents and internal conflicts: Can decentralization lift the curse?

We study how natural resource rents affect the risk of internal conflict within countries and how the federal structure of countries influences this relationship. Natural resource abundance may induce excessive rent-seeking and thus increase the risk of internal conflict. Fiscal and political decentralization as an institutional arrangement for rent-sharing and political codetermination of regions within a country may limit the destructive effect of natural resource rents on internal stability. Using cross-country and panel data from more than 90 countries covering the period 1984–2004, we find evidence that natural resource rents indeed increase the risk of internal conflict, but this relationship is significantly mitigated by political decentralization.