New lock box solution techniques have recently been suggested by Stone and Nauss-Markland. This paper briefly discusses these new methodologies and shows how the algorithms can be combined into a third solution procedure which exploits the computational efficiency of the Stone heuristic and...

It is widely assumed that common stock returns approximate a random walk, i.e., the returns are assumed to be serially independent. As a consequence, estimates of systematic risk and efficient portfolios are usually developed using any convenient differencing interval with the implication that...