Subjective Beliefs And Confidence When Facts Are Forgotten

Forgetting a piece of decision-relevant information is a salient source of uncertainty that should influence one's beliefs, confidence, and ambiguity attitudes. To investigate this, we run several experiments where people bet on propositions (facts) that they cannot recall with certainty. We use betting preferences to infer subjects' revealed beliefs and their revealed confidence in these beliefs. Forgetting is induced via interference tasks and time delays (up to one year). We observe a natural memory decay pattern where beliefs become less accurate and confidence is reduced as well. Moreover, we find a form of comparative ignorance where subjects are more ambiguity averse when they cannot recall the truth rather than never having learnt it. In a different vein, we identify an overconfidence pattern: on average, subjects overpay for bets on propositions that they believe in, but underpay for the opposite bets. We formulate a two-signal behavioral model of forgetting that generates all of these patterns. It suggests new testable hypotheses that are confirmed by our data.

100 Years Since Scott Reached the Pole: A Century of Learning About the Physiological Demands of Antarctica

The 1910–1913 Terra Nova Expedition to the Antarctic, led by Captain Robert Falcon Scott, was a venture of science and discovery. It is also a well-known story of heroism and tragedy since his quest to reach the South Pole and conduct research en route, while successful was also fateful. Although Scott and his four companions hauled their sledges to the Pole, they died on their return journey either directly or indirectly from the extreme physiological stresses they experienced. One hundred years on, our understanding of such stresses caused by Antarctic extremes and how the body reacts to severe exercise, malnutrition, hypothermia, high altitude, and sleep deprivation has greatly advanced. On the centenary of Scott's expedition to the bottom of the Earth, there is still controversy surrounding whether the deaths of those five men could have, or should have, been avoided. This paper reviews present-day knowledge related to the physiology of sustained man-hauling in Antarctica and contrasts this with the comparative ignorance about these issues around the turn of the 20th century. It closes by considering whether, with modern understanding about the effects of such a scenario on the human condition, Scott could have prepared and managed his team differently and so survived the epic 1,600-mile journey. The conclusion is that by carrying rations with a different composition of macromolecules, enabling greater calorific intake at similar overall weight, Scott might have secured the lives of some of the party, and it is also possible that enhanced levels of vitamin C in his rations, albeit difficult to achieve in 1911, could have significantly improved their survival chances. Nevertheless, even with today's knowledge, a repeat attempt at his expedition would by no means be bound to succeed.

The Analysis of Life Office Expenses

In turning over the pages of the Journal, one is struck by the number of papers which would have been rendered far more valuable if more detailed data of the actual expenses of management had been available. Probably less is known about expenses than about any other factor involved in our daily actuarial work; and this comparative ignorance is the more remarkable when we remember the immense amount of thought and research which has been expended on the subjects of Mortality and Interest.Perhaps good reasons existed in the past for this comparative neglect; but it appears to me that the time is approaching—if it has not already arrived—when it will be absolutely necessary to investigate the subject of expenses to the fullest possible extent. To mention only one aspect of the subject, there is a general impression that expenses are tending to increase, and hence it becomes important for each office to ascertain whether this impression is correct in its own case, and if so, the causes of the increase. These questions can only be answered by a full analysis; but if this is possible any increase will be robbed of much of its force, even if its cause cannot be removed. Certainly expenses are at least as worthy of investigation as mortality, and will probably yield more valuable results, since they, at least, are susceptible of regulation.