A simulation model of cereal-legume intercropping systems for semi-arid regions II. Model application

Smallholder farmers in Africa practice traditional cropping techniques such as intercropping. Intercropping is thought to offer higher productivity and resource milisation than sole cropping. In this study, risk associated with maize-bean intercropping was evaluated by quantifying long-term yield in both intercropping and sole cropping in a semi-arid region of South Africa (Bloemfontein, Free State) with reference to rainfall variability. The crop simulation model was run with different cultural practices (planting date and plant density) for 52 summer crop growing seasons (1950/1951-2001/2002). Eighty-one scenarios, consisted of three levels of initial soil water, planting date, maize population, and bean population, were simulated. From the simulation outputs, the total land equivalent ratio (LER) was greater than one. The intercrop (equivalent to sole maize) had greater energy value (EV) than sole beans, and the intercrop (equivalent to sole beans) had greater monetary value (MV) than sole maize. From these results, it can be concluded that maize-bean intercropping is advantageous for this semi-arid region. Soil water at planting was the most important factor of all scenario factors, followed by planting date. Irrigation application at planting, November/December planting and high plant density of maize for EV and beans for MV can be one of the most effective cultural practices in the study region. With regard to rainfall variability, seasonal (October-April) rainfall positively affected EV and MV, but not LER. There was more intercrop production in La Nina years than in El Nino years. Thus, better cultural practices may be selected to maximize maize-bean intercrop yields for specific seasons in the semi-arid region based on the global seasonal outlook. (c) 2004 Elsevier B.V. All rights reserved.

Monetary models of exchange rates and sweep programs

Numerous studies find that monetary models of exchange rates cannot beat a random walk model. Such a finding, however, is not surprising given that such models are built upon money demand functions and traditional money demand functions appear to have broken down in many developed countries. In this article, we investigate whether using a more stable underlying money demand function results in improvements in forecasts of monetary models of exchange rates. More specifically, we use a sweep-adjusted measure of US monetary aggregate M1 which has been shown to have a more stable money demand function than the official M1 measure. The results suggest that the monetary models of exchange rates contain information about future movements of exchange rates, but the success of such models depends on the stability of money demand functions and the specifications of the models.

Prepaid monetary incentives on mail survey response

Increasing mail survey response using monetary incentives is a proven, but not always cost-effective, method in every population. This paper tackles the questions of whether it is worth using monetary incentives and the size of the inducement by testing a regression model of the impact of prepaid monetary incentives on response rates in consumer and organizational mail surveys. The results support their use and show that the inducement value makes a significant impact on the effect size. Importantly, no significant differences were found between consumer and organizational populations.

The optimum prepaid monetary incentives for mail surveys

Increasing mail-survey response using monetary incentives is a proven, but not always cost-effective method in every population. This paper tackles the questions of whether it is worth using monetary incentives and the size of the inducement by testing a logit model of the impact of prepaid monetary incentives on response rates in consumer and organizational mail surveys. The results support their use and show that the inducement value makes a significant impact on the effect size. Importantly, no significant differences were found between consumer and organizational populations. A cost-benefit model is developed to estimate the optimum incentive when attempting to minimize overall survey costs for a given sample size. © 2006 Operational Research Society Ltd. All rights reserved.

Prepaid monetary incentives on mail survey response

Increasing mail survey response using monetary incentives is a proven, but not always cost-effective, method in every population. This paper tackles the questions of whether it is worth using monetary incentives and the size of the inducement by testing a regression model of the impact of prepaid monetary incentives on response rates in consumer and organizational mail surveys. The results support their use and show that the inducement value makes a significant impact on the effect size. Importantly, no significant differences were found between consumer and organizational populations.

Forecasting the UK/US exchange rate with divisia monetary models and neural networks

This paper compares the UK/US exchange rate forecasting performance of linear and nonlinear models based on monetary fundamentals, to a random walk (RW) model. Structural breaks are identified and taken into account. The exchange rate forecasting framework is also used for assessing the relative merits of the official Simple Sum and the weighted Divisia measures of money. Overall, there are four main findings. First, the majority of the models with fundamentals are able to beat the RW model in forecasting the UK/US exchange rate. Second, the most accurate forecasts of the UK/US exchange rate are obtained with a nonlinear model. Third, taking into account structural breaks reveals that the Divisia aggregate performs better than its Simple Sum counterpart. Finally, Divisia-based models provide more accurate forecasts than Simple Sum-based models provided they are constructed within a nonlinear framework.

Monetary models of exchange rates and sweep programs

Numerous studies find that monetary models of exchange rates cannot beat a random walk model. Such a finding, however, is not surprising given that such models are built upon money demand functions and traditional money demand functions appear to have broken down in many developed countries. In this paper we investigate whether using a more stable underlying money demand function results in improvements in forecasts of monetary models of exchange rates. More specifically, we use a sweepadjusted measure of US monetary aggregate M1 which has been shown to have a more stable money demand function than the official M1 measure. The results suggest that the monetary models of exchange rates contain information about future movements of exchange rates but the success of such models depends on the stability of money demand functions and the specifications of the models.

Evolution, recurrency and kernels in learning to model inflation

This paper provides the most fully comprehensive evidence to date on whether or not monetary aggregates are valuable for forecasting US inflation in the early to mid 2000s. We explore a wide range of different definitions of money, including different methods of aggregation and different collections of included monetary assets. We use non-linear, artificial intelligence techniques, namely, recurrent neural networks, evolution strategies and kernel methods in our forecasting experiment. In the experiment, these three methodologies compete to find the best fitting US inflation forecasting models and are then compared to forecasts from a naive random walk model. The best models were non-linear autoregressive models based on kernel methods. Our findings do not provide much support for the usefulness of monetary aggregates in forecasting inflation. There is evidence in the literature that evolutionary methods can be used to evolve kernels hence our future work should combine the evolutionary and kernel methods to get the benefits of both.

Gazdasági kormányzás a gazdasági és monetáris unióban - a globális politika lehetetlen szentháromsága szemszögéből (Economic governance in the economic and monetary union – applying the trilemma of global politics)

Az Európai Unió a világgazdaság egyik legfontosabb integrációja. A benne megvalósuló gazdasági integráció szorossága megfelel annak a szintnek, amit Rodrik hiperglobalizációnak nevez. Az elmélet szerint a politika szintjén egyszerre nem megvalósítható a demokratikus politikai döntéshozatal, a teljes világgazdasági integráció, illetve a nemzetállam. A trilemma a globalizáció útjában álló intézményi különbségeken alapszik. Megoldása három módon lehetséges: a demokrácia kiiktatásával a megoldás az arany kényszerzubbony, ahol a piaci mechanizmusok veszik át az állami gazdaságpolitika szerepét; a globális kormányzás megvalósulása esetén a szuverén nemzetállamok tűnnek el a nemzetközi rendszerből; végül a Bretton Woods kompromisszum esetében a globalizáció útjába állítunk akadályokat. Írásunkban a modellt az európai integrációra, egészen pontosan a Gazdasági és Monetáris Unióra alkalmazzuk. Érvelésünk szerint, ha fent kívánjuk tartani az integráció szorosságát, erősíteni kell az integráció szintjén a gazdasági kormányzást, ami pedig csak a tagállami szuverenitás rovására mehet. Ez, mely a GMU esetében leginkább a fiskális föderáció erősítését jelenti ugyanakkor, megnövelve az integráció költségeit, egy többsebességes Európa kialakulása irányába hathat. _____ The European Union with its sophisticated institutional system is the most important regional integration on Earth. This tight form of economic integration converges to the level that Dani Rodrik calls hyperglobalization in his model, the political trilemma of globalisation. In this model Rodrik assumes that from the three desired element of world politics (deep economic integration, the nation state, and democratic politics) only two can be chosen. We can either choose deep integration and the nation state but then we have to abandon democracy; or we can choose deep integration and democracy, but then we have to forfeit the nation state; or we have to circumscribe globalisation to maintain democracy and the nation state. In our paper we develop the mentioned model and then we apply it to the case of the European integration. We argue that if we want to maintain the deep integration among member states in the EU we have to pass more and more functions of the nation states to the federation level. In case of the EMU that means that federal fiscal policy is needed which could lead to multi-speed Europe considering new member states reluctance to give up their specific institutions.

Three essays on entrepreneurial motivation, entry, exit and monetary rewards

This dissertation analyzes rewards and motivations of self-employment. In light of recent research contributions of Barton Hamilton (2000), which find entrepreneurship not as financially rewarding as wage work, my dissertation attempts to both verify and explain this claim. The first essay proposes a theoretical model of evolution of erroneous earnings expectations on part of a nascent entrepreneur. Inability to observe, survey, and take into account all of the returns to entrepreneurship prior to business entry creates a biased set of beliefs on part of the potential entrants. Using Bayesian learning, a nascent entrepreneur starting out with correct perception of profit distribution arrives at erroneous beliefs by incorporating limited information collected from existing businesses. An observed distribution of surviving businesses would exhibit higher earnings because of previous, unobserved, business failure entrepreneur get an overly positive view of her profit potential. Hence, the chapter offers a unique method of modeling overconfidence. The second essay undertakes dynamic empirical comparison of earnings received by business owners and their wage counterparts. Using Survey of Income and Program Participation (SIPP) I examine both short and long run returns to entrepreneurship comparing theses rewards to wage earners returns. I pay particular attention to transitions into and out of business ownership. I estimate entire earnings distribution. To characterize dynamic aspect of changes to individuals’ earnings I split the income distribution into five income quintiles and follow survey participants over the period of seven years. I find that period-to-period transitions to be Markovian. I find business tenure to be short, business ownership is costly in the short and rewarding in the long run. The third essay considered different reporting schemes applied to the self-employed. It is another empirical investigation of entrepreneurial earning uses Panel Study of Income Dynamics (PSID). I find entrepreneurs while reporting lower than wage workers earnings enjoy significant consumption premiums. I observe evidence of income underreporting by entrepreneurs. This finding suggests a need for better earning comparison metrics and proposes to use consumption rather than income metrics for future comparisons.

The credit channel transmission of monetary policy in the European Union

This paper confirms the importance of the financial systems behaviour conditions to the credit channel of monetary policy in the entire European Union (EU). It uses panel fixed- effect estimations and quarterly data for 26 EU countries for the period from Q1 1999 to Q3 2006 in an adaptation of the Bernanke and Blinder (1988) model. The findings also reveal the high degree of foreign dependence and indebtedness of the EU banking institutions and their similar reactions to the macroeconomic and the monetary policy environments.

Performance determinants For Swedish Financial Monetary Institutions: Panel Data evidence between 2010-2014.

Due to the rapid changes that governs the Swedish financial sector such as financial deregulations and technological innovations, it is imperative to examine the extent to which the Swedish Financial institutions had performed amid these changes. For this to be accomplish, the work investigates what are the determinants of performance for Swedish Financial Monetary Institutions? Assumptions were derived from theoretical and empirical literatures to investigate the authenticity of this research question using seven explanatory variables. Two models were specified using Returns on Asset (ROA) and Return on Equity (ROE) as the main performance indicators and for the sake of reliability and validity, three different estimators such as Ordinary Least Square (OLS), Generalized Least Square (GLS) and Feasible Generalized Least Square (FGLS) were employed. The Akaike Information Criterion (AIC) was also used to verify which specification explains performance better while performing robustness check of parameter estimates was done by correcting for standard errors. Based on the findings, ROA specification proves to have the lowest Akaike Information Criterion (AIC) and Standard errors compared to ROE specification. Under ROA, two variables; the profit margins and the Interest coverage ratio proves to be statistically significant while under ROE just the interest coverage ratio (ICR) for all the estimators proves significant. The result also shows that the FGLS is the most efficient estimator, then follows the GLS and the last OLS. when corrected for SE robust, the gearing ratio which measures the capital structure becomes significant under ROA and its estimate become positive under ROE robust. Conclusions were drawn that, within the period of study three variables (ICR, profit margins and gearing) shows significant and four variables were insignificant. The overall findings show that the institutions strive to their best to maximize returns but these returns were just normal to cover their costs of operation. Much should be done as per the ASC theory to avoid liquidity and credit risks problems. Again, estimated values of ICR and profit margins shows that a considerable amount of efforts with sound financial policies are required to increase performance by one percentage point. Areas of further research could be how the individual stochastic factors such as the Dupont model, repo rates, inflation, GDP etc. can influence performance.

Credit spreads and monetary policy in a small open economy: an analysis of the colombian economy

This paper estimates Bejarano and Charry (2014)’s small open economy with financial frictions model for the Colombian economy using Bayesian estimation techniques. Additionally, I compute the welfare gains of implementing an optimal response to credit spreads into an augmented Taylor rule. The main result is that a reaction to credit spreads does not imply significant welfare gains unless the economic disturbances increases its volatility, like the disruption implied by a financial crisis. Otherwise its impact over the macroeconomic variables is null.

The Determinants of Individual Performance: Empirical Essays on the Importance of Soft Skills and Monetary Incentives

This dissertation consists of three papers. The first paper "Managing the Workload: an Experiment on Individual Decision Making and Performance" experimentally investigates how decision-making in workload management affects individual performance. I designed a laboratory experiment in order to exogenously manipulate the schedule of work faced by each subject and to identify its impact on final performance. Through the mouse click-tracking technique, I also collected interesting behavioral measures on organizational skills. I found that a non-negligible share of individuals performs better under externally imposed schedules than in the unconstrained case. However, such constraints are detrimental for those good in self-organizing. The second chapter, "On the allocation of effort with multiple tasks and piecewise monotonic hazard function", tests the optimality of a scheduling model, proposed in a different literature, for the decisional problem faced in the experiment. Under specific assumptions, I find that such model identifies what would be the optimal scheduling of the tasks in the Admission Test. The third paper "The Effects of Scholarships and Tuition Fees Discounts on Students' Performances: Which Monetary Incentives work Better?" explores how different levels of monetary incentives affect the achievement of students in tertiary education. I used a Regression Discontinuity Design to exploit the assignment of different monetary incentives, to study the effects of such liquidity provision on performance outcomes, ceteris paribus. The results show that a monetary increase in the scholarships generates no effect on performance since the achievements of the recipients are all centered near the requirements for non-returning the benefit. Secondly, students, who are actually paying some share of the total cost of college attendance, surprisingly, perform better than those whose cost is completely subsidized. A lower benefit, relatively to a higher aid, it motivates students to finish early and not to suffer the extra cost of a delayed graduation.

Integrated Proteomics Identified Up-regulated Focal Adhesion-mediated Proteins In Human Squamous Cell Carcinoma In An Orthotopic Murine Model.

Understanding the molecular mechanisms of oral carcinogenesis will yield important advances in diagnostics, prognostics, effective treatment, and outcome of oral cancer. Hence, in this study we have investigated the proteomic and peptidomic profiles by combining an orthotopic murine model of oral squamous cell carcinoma (OSCC), mass spectrometry-based proteomics and biological network analysis. Our results indicated the up-regulation of proteins involved in actin cytoskeleton organization and cell-cell junction assembly events and their expression was validated in human OSCC tissues. In addition, the functional relevance of talin-1 in OSCC adhesion, migration and invasion was demonstrated. Taken together, this study identified specific processes deregulated in oral cancer and provided novel refined OSCC-targeting molecules.