Wednesday, October 9, 2019

We Are Not Competent Combining Probability Forecasts: 60% and 60% Is 60%, but Likely and Likely Is Very Likely

Mislavsky, Robert and Gaertig, Celia, Combining Probability Forecasts: 60% and 60% Is 60%, but Likely and Likely Is Very Likely (September 16, 2019). SSRN: http://dx.doi.org/10.2139/ssrn.3454796

Abstract: How do we combine others’ probability forecasts? Prior research has shown that when advisors provide numeric probability forecasts, people typically average them (i.e., they move closer to the average advisor’s forecast). However, what if the advisors say that an event is “likely” or “probable?” In 7 studies (N = 6,732), we find that people “count” verbal probabilities (i.e., they move closer to certainty than any individual advisor’s forecast). For example, when the advisors both say an event is “likely,” participants will say that it is “very likely.” This effect occurs for both probabilities above and below 50%, for hypothetical scenarios and real events, and when presenting the others’ forecasts simultaneously or sequentially. We also show that this combination strategy carries over to subsequent consumer decisions that rely on advisors’ likelihood judgments. We find inconsistent evidence on whether people are using a counting strategy because they believe that a verbal forecast from an additional advisor provides more new information than a numerical forecast from an additional advisor. We also discuss and rule out several other candidate mechanisms for our effect.

Keywords: uncertainty, forecasting, verbal probabilities, combining judgments, combining forecasts, predictions

Higher levels of physical activity (outdoor play & sport participation) were associated with greater white matter microstructure in children; no association was observed between screen time and white matter microstructure

Associations of physical activity and screen time with white matter microstructure in children from the general population. María Rodriguez-Ayllon et al. NeuroImage, October 9 2019, 116258. https://doi.org/10.1016/j.neuroimage.2019.116258

Highlights
•    Higher levels of physical activity were associated with greater white matter microstructure in children.
•    Outdoor play and sport participation were specifically related to white matter microstructure.
•    No association was observed between screen time and white matter microstructure.

Abstract: Physical activity and sedentary behaviors have been linked to a variety of general health benefits and problems. However, few studies have examined how physical activity during childhood is related to brain development, with the majority of work to date focusing on cardio-metabolic health. This study examines the association between physical activity and screen time with white matter microstructure in the general pediatric population. In a sample of 2,532 children (10.12 ± 0.58 years; 50.04% boys) from the Generation R Study, a population-based cohort in Rotterdam, the Netherlands, we assessed physical activity and screen time using parent-reported questionnaires. Magnetic resonance imaging of white matter microstructure was conducted using diffusion tensor imaging. Total physical activity was positively associated with global fractional anisotropy (β = 0.057, 95% CI = 0.016, 0.098, p = 0.007) and negatively associated with global mean diffusivity (β = −0.079, 95% CI = −0.120, −0.038, p < 0.001), two commonly derived scalar measures of white matter microstructure. Two components of total physical activity, outdoor play and sport participation, were positively associated with global fractional anisotropy (β = 0.041, 95% CI=(0.000, 0.083), p = 0.047; β = 0.053, 95% CI=(0.010, 0.096), p = 0.015 respectively) and inversely associated with global mean diffusivity (β = −0.074, 95% CI= (−0.114, −0.033), p < 0.001; β = −0.043, 95% CI=(-0.086, 0.000), p = 0.049 respectively). No associations were observed between screen time and white matter microstructure (p > 0.05). This study provides new evidence that physical activity is modestly associated with white matter microstructure in children. In contrast, complementing other recent evidence on cognition, screen time was not associated with white matter microstructure. Causal inferences from these modest associations must be interpreted cautiously in the absence of longitudinal data. However, these data still offer a promising avenue for future work to explore to what extent physical activity may promote healthy white matter development.

Following a prolonged handshake (vs. a normal length or no handshake), participants showed less interactional enjoyment, as indicated by less laughing; also showed anxiety and behavioral freezing

Effects of Handshake Duration on Other Nonverbal Behavior. Emese Nagy et al. Perceptual and Motor Skills, October 8, 2019. https://doi.org/10.1177/0031512519876743

Abstract: Although detailed descriptions of proper handshakes partly comprise many etiquette books, how a normal handshake can be described, its proper duration, and the consequences of violating handshake expectations remain empirically unexplored. This study measured the effect of temporal violations of the expected length of a handshake (less than three seconds according to previous studies) administered unobtrusively in a naturalistic experiment. We compared volunteer participants’ (N = 34; 25 females; 9 males; Mage = 23.76 years, SD = 6.85) nonverbal behavior before and after (a) a prolonged handshake (>3 seconds), (b) a normal length handshake (average length <3 seconds), and (c) a control encounter with no handshake. Frame-by-frame behavioral analyses revealed that, following a prolonged handshake (vs. a normal length or no handshake), participants showed less interactional enjoyment, as indicated by less laughing. They also showed evidence of anxiety and behavioral freezing, indicated by increased hands-on-hands movements, and they showed fewer hands-on-body movements. Normal length handshakes resulted in less subsequent smiling than did prolonged handshakes, but normal length handshakes were also followed by fewer hands-on-face movements than prolonged handshakes. No behavior changes were associated with the no-handshake control condition. We found no differences in participants’ level of empathy or state/trait anxiety related to these conditions. In summary, participants reacted behaviorally to temporal manipulations of handshakes, with relevant implications for interactions in interviews, business, educational, and social settings and for assisting patients with social skills difficulties.

Keywords: behavior, handshake, nonverbal communication, behavioral analysis, phenomenology

California income tax 2012 increase of up to 3 pct points for high-income households: Outward migration and behavioral responses by stayers together eroded 45.2% of the windfall tax revenues from the reform

Behavioral Responses to State Income Taxation of High Earners: Evidence from California. Joshua Rauh, Ryan J. Shyu. NBER Working Paper No. 26349, October 2019. https://www.nber.org/papers/w26349

Abstract: Drawing on the universe of California income tax filings and the variation imposed by a 2012 tax increase of up to 3 percentage points for high-income households, we present new findings about the effects of personal income taxation on household location choice and pre-tax income. First, over and above baseline rates of taxpayer departure from California, an additional 0.8% of the California residential tax filing base whose 2012 income would have been in the new top tax bracket moved out from full-year residency of California in 2013, mostly to states with zero income tax. Second, to identify the impact of the California tax policy shift on the pre-tax earnings of high-income California residents, we use as a control group high-earning out-of-state taxpayers who persistently file as California non-residents. Using a differences-in-differences strategy paired with propensity score matching, we estimate an intensive margin elasticity of 2013 income with respect to the marginal net-of-tax rate of 2.5 to 3.3. Among top-bracket California taxpayers, outward migration and behavioral responses by stayers together eroded 45.2% of the windfall tax revenues from the reform.


Biological systems are fundamentally computational in that they process information in an apparently purposeful fashion rather than just transferring bits of it in a purely syntactical manner

Reflexivity, coding and quantum biology. Peter R Wills. Biosystems, Volume 185, November 2019, 104027. https://doi.org/10.1016/j.biosystems.2019.104027

Abstract: Biological systems are fundamentally computational in that they process information in an apparently purposeful fashion rather than just transferring bits of it in a purely syntactical manner. Biological information, such has genetic information stored in DNA sequences, has semantic content. It carries meaning that is defined by the molecular context of its cellular environment. Information processing in biological systems displays an inherent reflexivity, a tendency for the computational information-processing to be “about” the behaviour of the molecules that participate in the computational process. This is most evident in the operation of the genetic code, where the specificity of the reactions catalysed by the aminoacyl-tRNA synthetase (aaRS) enzymes is required to be self-sustaining. A cell’s suite of aaRS enzymes completes a reflexively autocatalytic set of molecular components capable of making themselves through the operation of the code. This set requires the existence of a body of reflexive information to be stored in an organism’s genome. The genetic code is a reflexively self-organised mapping of the chemical properties of amino acid sidechains onto codon “tokens”. It is a highly evolved symbolic system of chemical self-description. Although molecular biological coding is generally portrayed in terms of classical bit-transfer events, various biochemical events explicitly require quantum coherence for their occurrence. Whether the implicit transfer of quantum information, qbits, is indicative of wide-ranging quantum computation in living systems is currently the subject of extensive investigation and speculation in the field of Quantum Biology.