We study whether the Sarbanes-Oxley Act (SOX) of 2002 made firms less opaque. For identification, we use a difference-in-differences estimation approach and compare EU firms that are cross-listed in the US-and therefore subject to SOX-with comparable EU firms that are not cross-listed. We derive...

An analysis of about 300000 earnings forecasts, created by 18000 individual forecasters for earnings of over 300 S&P listed firms, shows that these forecasts are predictable to a large extent using a statistical model that includes publicly available information. When we focus on the...

We investigate the valuation of platform investment, such as asoftware operating system or anInternet portal WebPage. Platform investment is the creation of aninnovative distribution andproduction infrastructure, which increases access to customers; as aresult it reduces entry costs inrelated...

Any function from a non-empty polytope into itself that is locally gross direction preserving is shown to have the fixed point property. Brouwer's fixed point theorem for continuous functions is a special case. We discuss the application of the result in the area of non-cooperative game theory.

In this paper which will appear as a chapter in the Handbook ofGeneralized Convexity we discuss the basic ideas ofconvex and quasiconvex analysis in finite dimensional Euclideanspaces. To illustrate the usefulness of this branchof mathematics also applications to optimization theory...