Import-economic growth nexus in selected African countries: An application of the Toda-Yamamoto Granger non-causality test

We determine the nexus between imports and economic growth for a sample of 26 African countries for the period 1990-2015 within the neoclassical production function framework. We mainly contribute to literature by overcoming the weak theoretical modelling framework and possible model specification bias in most extant studies. Using the Toda-Yamamoto Granger non-causality test, the empirical results indicate that there is absence of causality between imports and economic growth in more than half of the countries in the sample, thus suggesting that neutrality hypothesis is predominant among the countries. We provide ample evidence that causality is absent from imports to economic growth. However, our results should be treated with caution because the absence of causality from imports to economic growth should not imply that imports do not play a role in the growth process of an economy.

Modeling Schistosoma japonicum Infection under Pure Specification Bias: Impact of Environmental Drivers of Infection

Keywords: schistosomiasis; pure specification bias; uncertainty; Bayesian statistics; convolution model

Comparing Survival Analysis and Discrete Choice Specifications Simulating Dynamics of Vehicle Ownership

Modeling travel-related decisions of transport system users is the core of many behavioral travel demand models. It is of great significance to use these models for planning purposes in which decisions of individuals are simulated for specific time intervals or on a continuous dimension until the target year. Discrete choice and survival analysis methods are two popular econometric structures to model and forecast time-dependent outcomes. This paper elaborates the conceptual and practical differences between these two methods in the context of vehicle ownership modeling. There are meaningful differences between these two methods including data preparation approaches, interpretations of the variable of interest in the model, and the simulation procedures. Further, this paper shows how negligent application of discrete choice methods for modeling time-to-event variables results in specification bias. This discussion paves the path for using hazard-based models in travel demand modeling, as the application of these models have been quite limited compared with their capacity.

Metodyczne aspekty wyceny dóbr publicznych na obszarach wiejskich: koncepcja waloryzacji endogenicznej = Methodical aspects of public goods valuation in rural areas: the concept of endogenous valuation

The aim of the study is to create a conceptual framework for the valuation of the endogenous influence of public goods in rural areas using the new approach: the economic surplus valuation method (ESV), which implements the concept of producer and consumer rent. A distinctive feature of the ESV, compared to other market-based valuation methods is the assumption that public goods exert an endogenous impact upon resources and their productivity, but do not act in the model as exogenous variables (as it is in the case of hedonic pricing methods; the HPM). The authors’ approach limits the issues related to the specification bias within the HPM. Moreover, this manner reduces the problems associated with model specification errors in the HPM. The authors argue that ignoring the endogenous impact of public goods on resources and their productivity can lead to distorted results.

Informação Endógena, Caracterização do Risco e Retornos de Ações Variantes no Tempo

In this paper we provide a new type of risk characterization of the predictability of two widely known abnormal patterns in average stock returns: momentum and reversal. The purpose is to illustrate the relative importance of common risk factors and endogenous information. Our results demonstrates that in the presence of zero-investment factors, spreads in average momentum and reversal returns correspond to spreads in the slopes of the endogenous information. The empirical findings support the view that various classes of firms react differently to volatility risk, and endogenous information harbor important sources of potential risk loadings. Taken together, our results suggest that returns are influenced by random endogenous information flow, which is asymmetric in nature, and can be used as a performance attribution factor. If one fails to incorporate the existing asymmetric endogenous information hidden in the historical behavior, any attempt to explore average stock return predictability will be subject to an unquantified specification bias.