Online Student Competitions in Economics

URL: http://www.econchallenge.org/     

Deterministic and stochastic trends in the time series models: a guide for the applied economist

Applied economists working with time series data face a dilemma in selecting between models with deterministic and stochastic trends. While models with deterministic trends are widely used, models with stochastic trends are not so well known. In an influential paper Harvey (1997 Harvey, AC. 1997. Trends, cycles and autoregression. Economic Journal, 107: 192–201. [Crossref] , [Google Scholar]) strongly advocates a structural time series approach with stochastic trends in place of the widely used autoregressive models based on unit root tests and cointegration techniques. Therefore, it is important to understand their relative merits. This article suggests that both methodologies are useful and they may perform differently in different models. This article provides a few guidelines to the applied economists to understand these alternative methods.     

The Volatility and Transmission of Equity Returns among the G-7 Countries: the post-Bretton Woods experience

This paper models the volatility of national stock market returns of the G-7 countries using ARCH and GARCH modeling techniques. Then, via the use of vector autoregression analysis, the international transmission of volatility among the countries is explored for the period between April 1973 and July 1990. Variance decompositions are calculated in order to quantify the impacts of volatility shocks in one market on the others. Impulse response functions are used to inspect the dynamic responses of domestic and foreign volatility shocks. Results indicate that volatility transmission among the G-7 countries is the norm in the post-Bretton Woods era. Further, we find that volatility shocks are generally absorbed within six to nine months.     

Developing and applying a framework to evaluate participatory research for sustainability

The normative implications of participatory research imply ongoing social learning that ought to lead to personal and institutional transformation. Sustainability science also requires reflexive scientific practice in order to enable the co-generation of solutions that take account of uncertainty and multiple forms of knowledge. However, there is little published peer-reviewed material on how to assess to what degree the rhetoric regarding the benefits of participatory research are achieved in practice, particularly with regard to participatory research for sustainability. This paper outlines how linking the rationales for participatory research and for sustainability science to the principles of evaluation can deliver a conceptually coherent evaluation framework for assessment. The approach for evaluating participatory research in this context consists of framing the evaluation, i.e., setting boundaries on the subject within its social, political, environmental and institutional context and selecting appropriate criteria, methods and data sources. The application of the framework, using a summative evaluation of participatory research for sustainability in north-east Australia, illustrates its strengths and weaknesses, concluding with a consideration of its applicability to further participatory sustainability science.     

On a rank-order test for the equality of probability of an event

Abstract

The following situation is considered. A fixed number (= n) or sequence of independent trials T ₁ T ₂,…, T _n is given, and in each of these an event E mayor may not occur, It is further observed that the event E occurs a total of k times amongst the n trials T _i , (i = l,…, n). It is then required to test the hypothesis H ₀ that the probability of the occurrence of E is constant from trial to trial, i.e. H ₀ is the hypothesis: p ₁ = p ₂ = ? = p _n = p, if p _n (i = 1, …, n) represents the probability that E occurs on the ith trial.     

Innovative productivity and returns to scale in the pharmaceutical industry

This study shows that firms in the pharmaceutical industry experience decreasing returns to scale in R & D as the level of R & D expenditures rises. The paper presents the results of our study of the innovative output of 16 pharmaceutical firms over a 19 year period. Given the strong correlation between R & D budgets and firm size, our study suggests the wave of mergers in the industry may yield less innovative productivity than managers expect.