Preferences for the resolution of uncertainty and the timing of information

We present results from a laboratory experiment designed to elicit preferences over the resolution of uncertainty and timing of non-instrumental information acquisition in a rich choice set. Treatments vary whether the uncertainty is framed as a compound lottery or information structure. We find that individuals prefer to delay uncertainty resolution when the choice is framed as a compound lottery and prefer to expedite uncertainty resolution when framed as an information structure. Preferences are strict, as individuals are willing to pay for information in one treatment and they pay to avoid information in the other. We find no evidence of an aversion to gradual resolution in either context

Dynamic risk preferences under realized and paper outcomes

We conduct a large-scale test of dynamic risk preferences. While most of the literature on dynamic risk restricts attention to positively skewed gambles, subjects in our experiment tend to choose negatively skewed lotteries. This allows us to study dynamic risk preferences in an environment that the literature has not analyzed. We find evidence of the reinforcement effect—individuals take on more risk after a gain and take on less risk after a loss. Furthermore, we exogenously vary whether these outcomes are “realized” or on paper, according to the distinction put forth by Imas (2016). We find little difference in the responses to realized and paper outcomes in environments of negatively skewed risk

Preferences for the resolution of uncertainty and the timing of information

We present results from a laboratory experiment designed to elicit preferences over the resolution of uncertainty and timing of non-instrumental information acquisition in a rich choice set. Treatments vary whether the uncertainty is framed as a compound lottery or information structure. We find that individuals prefer to delay uncertainty resolution when the choice is framed as a compound lottery and prefer to expedite uncertainty resolution when framed as an information structure. Preferences are strict, as individuals are willing to pay for information in one treatment and they pay to avoid information in the other. We find no evidence of an aversion to gradual resolution in either context

Refined Kirby calculus for integral homology spheres

A theorem of Kirby states that two framed links in the 3-sphere produce orientation-preserving homeomorphic results of surgery if they are related by a sequence of stabilization and handle-slide moves. The purpose of the present paper is twofold: First, we give a sufficient condition for a sequence of handle-slides on framed links to be able to be replaced with a sequences of algebraically canceling pairs of handle-slides. Then, using the first result, we obtain a refinement of Kirby's calculus for integral homology spheres which involves only +/-1-framed links with zero linking numbers.Comment: This is the version published by Geometry & Topology on 18 September 200

A Systematic Test of the Independence Axiom Near Certainty

A large literature has documented violations of expected utility consistent with a preference for certainty (the “certainty effect”). We design a laboratory experiment to investigate the role of the certainty effect in explaining violations of the independence axiom. We use lotteries spanning over the entire probability simplex to detect violations systematically. We find that violations of independence consistent with the reverse certainty effect are much more common than violations consistent with the certainty effect. Results hold as we test robustness along two dimensions: varying the mixing lottery and moving slightly away from certainty

When Choices are Mistakes

Using a laboratory experiment, we identify whether decision makers consider it a mistake to violate canonical choice axioms. To do this, we incentivize subjects to report which of several axioms they want their decisions to satisfy. Then, subjects make lottery choices which might conflict with their stated axiom preferences. We give them the opportunity to re-evaluate their decisions when lotteries conflict with desired axioms. We find that a majority of individuals want to follow the axioms and revise their lottery choices to be consistent with them. We interpret this to mean that most axiom violations in our sample were mistakes

Stable Randomization

We design a laboratory experiment to identify whether randomization behavior represents a stable “type” across different choice environments. In both games and individual choice questions, subjects face twenty simultaneous repetitions of the same choice. Randomization constitutes making different choices across the twenty repetitions. We find that randomization preferences are highly correlated across domains, with a sizable fraction of individuals randomizing in all domains, even in questions that offer a first-order stochastically dominant option. For some mixers, dominated randomization is responsive to intervention. Our results are inconsistent with many preference-based models of randomization, leaving open a role for heuristics and biases

Uterine Capacity and Ovulation Rate in Mice Selected 21 Generations on Alternative Criteria to Increase Litter Size

After 21 generations of selection for alternative criteria to change litter size in mice, responses in uterine capacity and ovulation rate were evaluated. Females from Generations 22 and 23 were sampled from 12 lines, representing three replicates of four selection criteria: LS = direct selection on litter size; M = selection on an index of ovulation rate and the proportion of ova shed that resulted in fully formed offspring; UT = selection on uterine capacity measured as litter size from females unilaterally ovariectomized at 4 wk of age; and LC = unselected control. All females in the present evaluation (a total of 1,932) were unilaterally ovariectomized (either left or right ovary excised) at 4 wk, mated at 9 wk, and killed at d 17 of gestation. The number of corpora lutea and number of fetuses were counted to measure ovulation rate and uterine capacity, respectively. Selection in IX, LS, and UT increased ( P \u3c .01) ovulation rate from unilaterally ovariectomized females but by a greater amount ( P \u3c .01) in IX and LS than in UT. Selection also increased (P \u3c . O l ) uterine capacity of IX, LS, and UT (average response relative to LC = 1.76 pups); response was at least as great in LS and IX as in UT. Direct selection in UT was successful at improving uterine capacity but was no more effective than IX or LS selection. Cases in which ovulation rate limited expression of uterine capacity in UT may have shifted some selection emphasis to ovulation rate and reduced response in uterine capacity

Uterine Mass and Uterine Blood Volume in Mice Selected 21 Generations for Alternative Criteria to Increase Litter Size

Lines of mice, selected for 21 generations using alternative criteria to increase litter size, were evaluated for uterine mass and uterine blood volume to help explain differences in uterine capacity. For this study, mice were sampled from Generation 27, the sixth generation after relaxation of selection. Mice came from all four criteria of selection (LS = selection on number born to unaltered females; M = selection on an index of ovulation rate and ova success; UT = selection on uterine capacity; and LC = unselected control) in each of three replicates (a total of 12 lines). Measurement was at one of two stages, either 3 d or 6 d of gestation. Matings were at 10 wk of age, and a total of 508 mice (17 to 26 per line-day of pregnancy subclass) were measured. The mean of the three selected groups exceeded the control in uterine mass ( P \u3c .001), uterine blood volume ( P \u3c .002), uterine mass/body mass (P \u3c .03), and uterine blood volume/body mass ( P \u3c .04 ) but not in uterine blood volume/uterine mass. Greater uterine mass and concomitantly greater uterine blood volume may have been partly responsible for greater uterine capacity resulting from LS, M, and UT selections