Distance-based accessibility indices

The paper attempts to develop a suitable accessibility index for networks where each link has a value such that a smaller number is preferred like distance, cost, or travel time. A measure called distance sum is characterized by three independent properties: anonymity, an appropriately chosen independence axiom, and dominance preservation, which requires that a node not far to any other is at least as accessible. We argue for the need of eliminating the independence property in certain applications. Therefore generalized distance sum, a family of accessibility indices, will be suggested. It is linear, considers the accessibility of vertices besides their distances and depends on a parameter in order to control its deviation from distance sum. Generalized distance sum is anonymous and satisfies dominance preservation if its parameter meets a sufficient condition. Two detailed examples demonstrate its ability to reflect the vulnerability of accessibility to link disruptions.

Formalization of the informal venture capital market - Business angel networks and syndicates

Business angels are natural persons who provide equity financing for young enterprises and gain ownership in them. They are usually anonym investors and they operate in the background of the companies. Their important feature is that over the funding of the enterprises based on their business experiences they can contribute to the success of the companies with their special expertise and with strategic support. As a result of the asymmetric information between the angels and the companies their matching is difficult (Becsky-Nagy – Fazekas 2015), and the fact, that angel investors prefer anonymity makes it harder for entrepreneurs to obtain informal venture capital. The primary aim of the different type of business angel organizations and networks is to alleviate this matching process with intermediation between the two parties. The role of these organizations is increasing in the informal venture capital market compared to the individually operating angels. The recognition of their economic importance led many governments to support them. There were also public initiations that aimed the establishment of these intermediary organizations that led to the institutionalization of business angels. This study via the characterization of business angels focuses on the progress of these informational intermediaries and their ways of development with regards to the international trends and the current situation of Hungarian business angels and angel networks.