The role of public intervention in R & D

The purpose of this paper is threefold: (1) we emphasize the rule of uncertainty in achieving an efficient allocation of resources to R & D activities; (2) we identify and discuss optional mechanisms that are directed at minimizing the role of uncertainty in determining R & D decisions; and (3) we analyze the role of public intervention in R & D via a formal structure. More specifically, we explain why and under what conditions a risk-averse decision-maker will invest less than a government in research and inventive activities. Sufficient conditions that lead to private underinvestment in these activities are established. Furthermore, if the option of buying information exists, then we identify a set of private governmental contracts that may lead to the acceptance of a research project that a priori is unfeasible.     

A note on Model Reference Adaptive System (MRAS) estimate with infinite variance

This paper discusses the estimation of a parameter in an autoregressive model with infinite variance. A recursive estimation procedure based on minimizing the prediction errors is provided. It is also shown that the model reference adaptive system estimate for an AR (1) model given in Aase (1983) is a special case.     

Testing the Random Walk Behavior and Efficiency of the Gulf Stock Markets

Inferences drawn from tests of market efficiency are rendered imprecise in the presence of infrequent trading. As the observed index in thinly traded markets may not represent the true underlying index value, there is a systematic bias toward rejecting the efficient market hypothesis. For the three emerging Gulf markets examined in this paper, correction for infrequent trading significantly alters the results of market efficiency and random walk tests. The Beveridge–Nelson (1981) decomposition of index returns is done to estimate the underlying index.     

Day‐of‐the‐Week Effect in High Moments

Evidence from equity markets worldwide indicates that the Day‐of‐the‐Week anomaly appears to fade from the first moment of the distribution of daily returns. We report highly significant pair‐wise weekend effects in high moments when comparing the first and last trading days of the week. The second moment alone appears to distinguish the return distribution of the first trading day from all others. A probable explanation of the phenomena appears to be information dissemination: corporate announcements released after closing of the last trading day of the week spill‐over to the opening of the first trading day, increasing its variability and carrying the closing sign.