Neoclassical growth model with two fixed delays

“Delay” has been considered as one of destabilizing factors in economic dynamics for a long time. Dynamic macroeconomics is concerned with explaining growth and fluctuations. This paper shows how various dynamics involving cyclic fluctuations can emerge in the standard neoclassical growth model when two distinct delays, a delay in production and a delay in depreciation, are explicitly taken into account. We first confirm that the production delay has a stabilizing effect and the depreciation delay has a destabilizing effect in a one‐delay model. We then determine the stability switching curve analytically in the two delay model. It is shown that cyclic fluctuations emerge via Hopf bifurcation when stability is lost. It is also found that stability loss and gain repeatedly occur. Numerical examples verify the theoretical results when the Cobb‐Douglas production function is adopted.     

Partitioning uncertain workloads

We present a method for determining the ratio of the tasks when breaking any complex workload in such a way that once the outputs from all tasks are joined, their full completion takes less time and exhibit smaller variance than when running on the undivided workload. To do that, we have to infer the capabilities of the processing unit executing the divided workloads or tasks. We propose a Bayesian Inference algorithm to infer the amount of time each task takes in a way that does not require prior knowledge on the processing unit capability. We demonstrate the effectiveness of this method in two different scenarios; the optimization of a convex function and the transmission of a large computer file over the Internet. Then we show that the Bayesian inference algorithm correctly estimates the amount of time each task takes when executed in one of the processing units.     

A threshold model for respondent heterogeneity

Continuous models of respondent heterogeneity assume the existence of a response function where variables of interest are continuously related to explanatory variables. In many situations this assumption may not be true. In this paper we propose an approach of modeling respondent heterogeneity that identifies abrupt changes in the distribution of response coefficients around a threshold specification. Our model differs from traditional threshold models by introducing the threshold effect to describe across-unit behavior as opposed to within-unit behavior. We illustrate our proposed Bayesian threshold model for survey data from a large national retail bank that examines the effects of service wait times on customer satisfaction. We find evidence of a threshold effect where long in-process wait times are associated with bank branches characterized by weak associations between service quality drivers and overall perceptions of service quality. Branches with wait times below the threshold are found to have much stronger associations.     

Exchange‐rate Misalignments in Duopoly: The Case of Airbus and Boeing

We examine the effect of exchange‐rate misalignments on competition in the market for large commercial aircraft. This market is a duopoly where players compete in dollar‐denominated prices while one of them, Airbus, incurs a large fraction of its costs in euro. We estimate price elasticities for big aircraft, and construct a simulation model to investigate how companies adjust their prices to deal with the effects of a temporary misalignment and how this affects profit margins and volumes. We conclude that, due to the duopolistic nature of the aircraft market, Airbus will pass only a small part of the exchange‐rate fluctuations on to customers. Moreover, due to features specific to the aircraft industry, such as customer switching costs and learning‐by‐doing, even a temporary departure of the exchange rate from its long‐run equilibrium level may have permanent effects on the industry.     

Examining critical and near-critical paths: an Excel-based classroom exercise

The author’s goals in this exercise were to use an Excel project to teach students about the effects of changing states of nature on critical path emergence as well as compare the impact of the PERT beta and triangular distributions on project completion times. Previous research into the PERT (program evaluation and review technique) beta distribution indicated a tendency for this distribution to overstate the impact of the dominant critical path on project completion times. The author used a Monte Carlo simulation and a new Excel function to explore the effects of random variation on critical path emergence. He used both the triangular distribution and the PERT beta distribution to calculate project completion times. The author found that three of the possible five paths became critical in both the PERT beta and triangular distributions. However, the triangular distribution moderated the PERT beta distribution’s tendency toward the dominate critical path.     

Female labour force participation and labour saving gadgets

Abstract

We show under what conditions women would migrate out of the household sector into formal sector jobs, in response to increased ability to use labour saving household gadgets, which raise the productivity of female labour engaged in household tasks. We model a small open economy with three outputs: one labour-intensive manufactured export (cloth), one capital-intensive intermediate good (gadgets) and one non-traded ‘household-sector good’ (meals) which requires both female labour and household gadgets for production. A terms-of-trade improvement capturing greater world demand for labour-intensive manufactured exports enables greater adoption of labour-saving household gadgets in response to changing relative prices. If the elasticity of substitution between female labour and household gadgets exceeds a threshold, this will result in women migrating from the household to formal sector employment. What matters is not the actual date of invention of these labour-saving appliances (female labour force participation may not grow significantly until long after) but their increased adoption by the small economy in response to changing relative prices.     

国际大米市场价格波动对国内市场的传递效应——基于误差修正模型的估计

基于2006年2月—2011年3月的月度数据,对国际大米价格波动与中国国内大米价格波动的长期均衡关系进行检验,分析国内大米价格波动的主要影响因素及其程度,考察国内外大米市场价格波动的时滞效应与调整效应,并从外贸途径和期货途径测度国外大米价格波动对国内大米价格波动的传导效应,基本结论是:国际大米价格波动与国内大米价格波动存在长期稳定的均衡关系,长期内国内大米价格波动主要由通货膨胀带动,且价格传递具有明显的时滞效应和调节效应。脉冲响应函数和方差分解方法实证结果表明,国际大米价格通过外贸渠道和期货渠道对国内大米价格产生影响,其中期货途径对国内大米价格波动的传导效应更显著。     

Critical success factors in project management: implication from Vietnam

This study will assess successful project performance based on key project factors. The indicators of project success are cost, time, technical performance and customer satisfaction as used in previous studies. The sample consisted of 239 project members and managers currently involved in infrastructure projects in Vietnam. Regression analysis was used to test five hypotheses developed from theories on project success. Three groups of factors including manager competencies, member competencies and external stability have significant positive relationships to the success criteria. The completion and implementation stages in the project life cycle are also positively related to success. The implementation stage of a project moderates both the effects of external stability and organization support on success. The implication for project managers is that implementation is the key stage in determining the success of projects.     

一种基于Levy-人工蜂群的三维Otsu阈值分割算法

针对图像分割过程中三维Otsu算法运算时间长、计算量大的问题,提出了一种基于Levy-人工蜂群算法的三维Otsu阈值分割算法。首先,以像素灰度值-邻域均值-邻域中值的三维类间方差作为人工蜂群算法的适应度函数;其次,采用Levy飞行模式评价像素的适应度,对其种群更新及邻域搜索过程进行优化,以增强其全局搜索能力;最后,利用改进后的算法得到的分割阈值对图像进行分割。仿真实验结果表明,与传统三维Otsu阈值分割算法相比,所提算法能够有效降低图像存储空间,处理时间降低了30.8%,具备更好的抗噪性能,分割效果也更为理想。     

Asymmetric Price Adjustment in the US Gasoline Industry: Evidence from Bayesian Threshold Dynamic Panel Data Models

This paper investigates the gasoline price adjustment to changes in the input cost price for a panel of 48 US states using a monthly data set covering the period 1994–2011. We build, for the first time, a non-linear threshold panel vector-error-correction model (PVECM) and propose efficient Markov chain Monte Carlo (MCMC) Bayesian techniques. Our findings indicate that states with high margin experience a slower adjustment and a more asymmetric response to input price cost shocks. Our results are robust to potential structural breaks in the threshold parameter, which is important as market conditions change over time and are very sensitive to production/consumption constraints. Lastly, we attribute fluctuations in the gasoline prices to input cost shocks, arguing that the peak responses occurring one month after the shock are short-lived.     

Delay Dynamics in a Classical IS‐LM Model with Tax Collections

An IS‐LM model is developed for the dynamics of income, interest rate and money stock with delay in tax revenue. The main aim is to show that the delay matters in macro dynamics. Two different delays, fixed time delays and continuously distributed time delays, are considered explicitly and described by delay‐differential equations and integro‐differential equations, respectively. Conditions for the local stability of the two models are derived and compared. The destabilizing effects caused by the delay are numerically examined. Appearance of wide spectrum of dynamics ranging from simple cyclic oscillations to complex dynamics is described through Hopf bifurctions.     

Demand-side stabilization policies: What is the evidence of their potential?

Using disaggregated data for the United States, this paper explores the effects of the variability of fiscal and monetary policy shocks. Higher variability of government spending shocks around a steady-state growth trend results in, on average, a decline in aggregate demand growth and inflation, with limited effects on output growth. On the other hand, higher variability of monetary shocks results in, on average, an increase in inflation and a decline in output growth. These results indicate the desirability of avoiding large fluctuations over time in either government spending or the money supply.     

HEURISTIC EXPECTATION FORMATION AND BUSINESS CYCLES: A SIMPLE LINEAR MODEL

We develop a Keynesian business cycle model to study how extrapolative and regressive expectation formation rules may affect fluctuations in economic activity. We find that simple expectation formation rules may have an impact on the level and the stability of the equilibrium income, the size of the multiplier and the resulting adjustment process after an exogenous shocks. Our model also reveals that national income may be influenced by how agents perceive their long‐run average income.     

The de minimis threshold in international trade: The costs of being too low

With tariffs largely negotiated away, trade facilitation issues such as custom delays and border costs are one of the next key barriers for trade policymakers to address. One important trade facilitation issue is the de minimis threshold (DMT )—a valuation ceiling for imports below which no duty or tax is charged and the clearance procedures are minimal. Customs assessments are costly and low thresholds can hinder trade flows. We offer a detailed analytical approach to assess the direct economic effects of raising the DMT . We focus on Canada, which has one of the lowest DMT s among developed countries. We utilise a unique data set and find that raising Canada's DMT would have positive effects for consumers and businesses, particularly small businesses because the cost saving for smaller entities is disproportionately large. For the government, foregone duty and tax revenues are outweighed by the cost saving, resulting in a fiscally neutral or even positive effect for government revenues.     

Dynamic Global Linkages of the BRICS Stock Markets with the United States and Europe Under External Crisis Shocks: Implications for Portfolio Risk Forecasting

Crisis shocks often lead to changes in the interdependence across stock markets and thus affect risk assessment and management. This paper investigates the extent to which the global financial crisis of 2008–09, which was triggered by the US subprime crisis in 2007, and the European debt crisis that started at the end of 2009, affects the interdependence of the leading emerging markets of the BRICS countries with those of the United States and Europe. Our empirical analysis makes use of the FIAPARCH model combined with the Dynamic Equicorrelation (DECO‐FIAPARCH), which allows for the estimation of market linkage for a large group of countries as a whole, while controlling for asymmetric volatility and long memory. The results reveal the presence of important changes in the time‐varying linkages of the BRICS stock markets with the US and European ones. In particular, the average linkages have significantly been higher between 2007 and the first half of 2012 than the remaining part of the sample, and there is also evidence of a structural change around the Lehman Brothers collapse. We also show the effects of these stylised facts on portfolio risk assessment and forecasting.     

An Empirical Analysis of the Determinants of Interest Rates in Ghana

ABSTRACT

This paper provides an empirical analysis of the determinants of the bank lending rate in Ghana using annual time series data from 1970 to 2013. We found evidence of a long-run equilibrium relationship between the average lending rate charged by commercial banks and its determining factors. In the long run, bank lending rates in Ghana are positively influenced by nominal exchange rates and Bank of Ghana’s monetary policy rate but negatively with fiscal deficit, real GDP and inflation. We also find positive dependence of the bank lending rate on exchange rates, and the monetary policy rate both in the short and long run. Specifically, our findings reveal that the Bank of Ghana’s monetary policy rate and the exchange rate, by far, show strong contemporaneous effects on the average bank lending rate in Ghana.     

Comovement in GDP trends and cycles among trading partners

It has long been recognized that business cycle comovement is greater between countries that trade more intensively with one another. However, nations face shocks to both the cyclical and trend components of their GDP series. Contrary to the result for cyclical fluctuations, we find comovement of shocks to the trend component of real GDP is weaker among countries that trade more intensively with one another. We simulate changes in ten-year output growth correlations corresponding to the estimated effects of trade and show that the impact of trade on trend comovement is quantitatively more important than its effect on cyclical comovement.     

Comovement in GDP trends and cycles among trading partners

It has long been recognized that business cycle comovement is greater between countries that trade more intensively with one another. However, nations face shocks to both the cyclical and trend components of their GDP series. Contrary to the result for cyclical fluctuations, we find comovement of shocks to the trend component of real GDP is weaker among countries that trade more intensively with one another. We simulate changes in ten-year output growth correlations corresponding to the estimated effects of trade and show that the impact of trade on trend comovement is quantitatively more important than its effect on cyclical comovement.     

An Empirical Model of Advertising Dynamics

This paper develops a model of dynamic advertising competition, and applies it to the problem of optimal advertising scheduling through time. In many industries we observe advertising “pulsing”, whereby firms systematically switch advertising on and off at a high-frequency. Hence, we observe periods of zero and non-zero advertising, as opposed to a steady level of positive advertising. Previous research has rationalized pulsing through two features of the sale response function: an S-shaped response to advertising, and long-run effects of current advertising on demand. Despite considerable evidence for advertising carry-over, existing evidence for non-convexities in the shape of the sales-response to advertising has been limited and, often, mixed. We show how both features can be included in a discrete choice based demand system and estimated using a simple partial maximum likelihood estimator. The demand estimates are then taken to the supply side, where we simulate the outcome of a dynamic game using the Markov perfect equilibrium (MPE) concept. Our objective is not to test for the specific game generating observed advertising levels. Rather, we wish to verify whether the use of pulsing (on and off) can be justified as an equilibrium advertising practice. We solve for the equilibrium using numerical dynamic programming methods. The flexibility provided by the numerical solution method allows us to improve on the existing literature, which typically considers only two competitors, and places strong restrictions on the demand models for which the supply side policies can be obtained. We estimate the demand model using data from the Frozen Entree product category. We find evidence for a threshold effect, which is qualitatively similar to the aforementioned S-shaped advertising response. We also show that the threshold is robust to functional form assumptions for the marginal impact of advertising on demand. Our estimates, which are obtained without imposing any supply side restrictions, imply that firms should indeed pulse in equilibrium. Predicted advertising in the MPE is higher, on average, than observed advertising. On average, the optimal advertising policies yield a moderate profit improvement over the profits under observed advertising.JEL Classification: L11, L66, M30 M37 R12     

Perceptions of download delays: relation to actual waits,web site abandoning,and stage of delay

This experiment investigates how slow downloads of shopping web sites are perceived by online consumers, and how download delays relate to web site abandoning and stage of delay. Results show a complex, nonlinear relationship between actual and perceived download waiting, where perceptions level off after a threshold is reached. Furthermore, perceptions of download waiting are found to be more reliable than actual waits in predicting web site abandoning. Finally, delays near the start of the download are perceived as longer than later in the process, and time pressure worsens the effect of download waiting at earlier stages of delay.