We provide a Matlab quadratic optimization tool based on Markowitz's critical line algorithm that significantly outperforms standard software packages and a recently developed operations research algorithm. As an illustration: For a 2000 asset universe our method needs less than a second to...

We consider a firm A initially owning a software platform (e.g. operating system) and an application for this platform. The specific knowledge of another firm B is needed to make the platform successful by creating a further application. When B's application is completed, A has incentives to...

Mechanisms where sellers set the price and are charged a linear commission fee are widely used by real world intermediaries, e.g. by real estate brokers. Empirically these commission fees exhibit very little variance, both across heterogeneous regional markets and over time. So far, there is no...

We provide a Matlab quadratic optimization tool based on Markowitz's citical line algorithm that significantly outperforms standard software packages and a recently developed operations research algorithm. As an illustration: For a 2000 asset universe our method needs less than a second to...

We consider a software vendor selling both a monopoly platform (e.g. operating system) and an application that runs on this platform. He may face competition by an entrant in the applications market. Consumers are heterogeneous in their preferences for both the platform and the applications....

We consider a software vendor first selling a monopoly platform and then an application running on this platform. He may face competition by an entrant in the applications market. The platform monopolist can benefit from competition for three reasons. First, his profits from the platform...