More nonconcavities in information processing functions

The productivity of (human) information processing as an economic activity is a question that is raising some interest. Using Marschak's evaluation framework, Radner and Stiglitz have shown that, under certain conditions, the production function of this activity has increasing marginal returns in its initial stage. This paper shows that, under slightly different conditions, this information processing function has repeated convexities with ongoing processing activity. Even for smooth changes in the signals' likelihoods, the function is only piecewise smooth with non-differentiable convexities at points of conditional changes of action. For linear likelihood functions the processing value proves to be piecewise linear with convexities at these levels. This revised version was published online in June 2006 with corrections to the Cover Date.     

A common-features analysis of Amsterdam and London financial markets during the eighteenth century

We examine the financial linkage between the London and Amsterdam financial markets using stock prices recorded in each market over the period 1723-94 in conjunction with tests for common trends, cycles, and regime shifts. These tests reveal a surprising degree of integration between the markets as their prices move together in both the short and long run. Moreover, shocks to the assets translate quickly and accurately between markets. It also appears that Dutch investment did not destabilize London markets and stock prices in London were the primary determinant of prices in Amsterdam.     

Prevalence Estimates of Gambling Participation and Problem Gambling among 16–18-year-old Students in Iceland: A Comparison of the SOGS-RA and DSM-IV-MR-J

The aim of this study was to estimate gambling participation and problem gambling among Icelandic adolescents. Participants were 750 16–18-year-old students, 371 girls and 379 boys. The rate of problem gambling was estimated with the SOGS-RA and DSM-IV-MR-J. Results indicated that 96% of adolescents had gambled in their lifetime, 79% at least once in the preceding year and about 10% gamble at least once a week. A psychometric evaluation of the two screening scales revealed satisfactory reliabilities and factor structures for both scales. The DSM-IV-MR-J identified 2% of the participants as problem gamblers while SOGS-RA identified 2.7%, and problem gambling was more common among boys than girls. It was concluded that problem gambling among adolescents is an area of concern for the Icelandic community that needs to be further investigated.     

Outcome of an interdisciplinary pain management program in a rehabilitation clinic

The Chronic Pain Section at Reykjalundur has 33 beds for patients with various chronic pain problems. About 200 patients are treated annually. For 3 years, 158 patients were enrolled in a random study focusing on increasing the patients' functioning and eliminating analgesic drugs through an interdisciplinary rehabilitation program. Patients answered a questionnaire at admission, before discharge from the clinic and about one year after discharge. The follow-up was done with a mailed questionnaire. The focus was on the patients' functioning rather than absence of pain. The program's duration was 7 weeks. The first 2 weeks were utilized for evaluation, information and education (pain school). Pain relieving drugs were gradually withdrawn but anti-inflammatory drugs were used when indicated. Cognitive behavioral therapy was applied in an increasing number of cases over the 3 year period by specially trained nurses and a psychiatrist. Pain, anxiety and depression were self-evaluated on a numeric rating scale (NRS). About 50% of the patients had a history of pain for more than 5 years. Low back pain was the most common diagnosis (48.1%) and 28.5% had post-traumatic pain. A significant reduction in pain, anxiety and depression was found both at discharge (p < 0.0001) and at follow-up (p < 0.001). Before entering the program, only 18.4% of the patients were able to work whereas 48.1% returned to work after discharge and 59.2% were working at follow-up.