Credit ratings affect firms’ access to capital and investment choices. We show that the identity of the credit analysts covering a firm significantly affects the firm’s rating, comparing ratings for the same firm at the same time across agencies. Analyst effects account for 30% of the within variation in ratings. Moreover, the rating biases of analysts carry through to credit spreads on the rat...

We propose a simple agent-based macroeconomic model in which firms hold heterogeneous sales expectations. A firm may either optimistically expect an increase in its sales or pessimistically expect the opposite. Whether a given firm is optimistic or pessimistic depends on macroeconomic conditions and the average mood prevailing within its social/local neighborhood. For instance, the probability ...

Linguistic negation processing is a challenging problem studied by a large number of researchers from different communities, i.e. logic, linguistics, etc. We are interested in finding the positive interpretations of a negative sentence represented as ”x is not A”. In this paper, we do not focus on the single set of translations but on two approximation sets. The first one called pessimistic cor...

In this paper, we propose a novel optimistic unchoking approach for the BitTorrent protocol whose key objective is to improve the quality of inter-connections amongst peers. In turn, this yields enhanced data distribution without penalizing underutilized and/or idle peers. The suggested policy takes into consideration the number of peers currently interested in downloading from a client that is...

Replication is attractive for scaling databases up, as it does not require costly equipment and it enables fault tolerance. However, as the latency gap between local and remote accesses continues to widen, maintaining consistency between replicas remains a performance and complexity bottleneck. Optimistic replication (OR) addresses these problems. In OR, a database tentatively executes transact...

This paper, based on the average monthly data (January, 2001 to May, 2013) of 12 macroeconomic variables, uses the data reduction technique-factor analysis to derive the factors which determine the performance of stock market in India. The Principal Component Technique after using orthogonal rotation extracted three factors labeled intuitively as Macro Environment, Industrial Performance and Po...

In this work we study the problem of QoS routing under inaccurate link state. In particular we compare the efficiency of different link cost functions in a realistic environment where the link state changes cannot be immediately communicated to all the nodes in the network. We also analyse the effects of predicting the present network state when a node must make a routing decision. For this pur...

Efficiency of optimistic fair exchange using trusted devices is studied. Pfitzmann, Schunter and Waidner (PODC 1998) have shown that four messages in the main sub-protocol is optimal when exchanging idempotent items using non-trusted devices. It is straightforward that when using trusted devices for exchanging nonidempotent items this number can be reduced to three. This however comes at the co...

This paper presents the Optimistic Atomic Broadcast algorithm (OPT-ABcast) which exploits the spontaneous total order message reception property experienced in local area networks in order to allow fast delivery of messages. The OPT-ABcast algorithm is based on a sequence of stages, and messages can be delivered during a stage or at the end of a stage. During a stage, processes deliver messages...

We make a number of remarks about the AES-GCM-SIV nonce-misuse resistant authenticated encryption scheme currently considered for standardization by the Crypto Forum Research Group (CFRG). First, we point out that the security analysis proposed in the ePrint report 2017/168 is incorrect, leading to overly optimistic security claims. We correct the bound and re-assess the security guarantees off...