This paper improves upon the existing literature surrounding the production order quantity inventory model in which unit cost and daily production are assumed to be constant. By including economies of scale into the model, we examine its impact on production order quantity and total cost. The...

Land subsidence created by underground coal mining has a critical influence on the structure and function of ecosystems in mining areas. However, knowledge of the aquatic bacterial community structure and interspecies interactions in subsidence lake is still limited. To address this, we...

We propose a new measure of portfolio activity, the Modified Turnover, which represents the portion of the portfolio that the manager changes from one quarter to the next. Compared with the traditional turnover, our Modified Turnover measure relies on portfolio holdings and takes into account...

Interest in socially responsible investing (SRI) has skyrocketed within the mutual fund industry. Central to this development is whether SRI funds underperform conventional funds. Using a novel approach, we decompose mutual fund portfolios into socially responsible (green) and non-socially...