EXPRESS: Extremity Bias in Online Reviews: The Role of Attrition

In a range of studies across platforms, online ratings have been shown to be characterized by distributions with disproportionately-heavy tails. We focus on understanding the underlying process that yields such “j-shaped” or “extreme” distributions. We propose a novel theoretical mechanism behind the emergence of “j-shaped” distributions: differential attrition, or the idea that potential reviewers with moderate experiences are more likely to leave the pool of active reviewers than potential reviewers with extreme experiences. We present an analytical model that integrates this mechanism with two extant mechanisms: differential utility and base rates. We show that while all three mechanisms can give rise to extreme distributions, only the utility-based and the attrition-based mechanisms can explain our empirical observation from a large-scale field experiment that an unincentivized solicitation email from an online travel platform reduces review extremity. Subsequent analyses provide clear empirical evidence for the existence of both differential attrition and differential utility.

Differential Utility: Accounting for Correlation in Performance Among Design Alternatives

Recognizing expected utility as a valid design criterion, there are cases where uncertainty is such that this criterion fails to distinguish clearly between design alternatives. These cases may be characterized by broad and significantly overlapping utility probability distributions. Not uncommonly in such cases, the utility distributions of the alternatives may be highly correlated as the result of some uncertain variables being shared by the alternatives, because modeling assumptions may be the same across alternatives, or because difference information may be obtained by means of an independent source. Because expected utility is evaluated for alternatives independently, maximization of expected utility typically fails to take these correlations into account, thus failing to make use of all available design information. Correlation in expected utility across design alternatives can be taken into account only by computing the expected utility difference, namely the “differential expected utility,” between pairs of design alternatives. However, performing this calculation can present significant difficulties of which excessive computing times may be key. This paper outlines the mathematics of differential utility and presents an example case, showing how a few simplifying assumptions enabled the computations to be completed with approximately 24 hours of desktop computing time. The use of differential utility in design decision making can, in some cases, provide significant additional clarity, assuring better design choices.

Coercive Controlling Behaviors and Reporting Physical Intimate Partner Violence in Australian Women: An Exploration

This study explores two approaches to measuring coercive controlling behaviors (CCBs)—counting how many different CCB types and examining the frequency of each CCB experienced—to examine their utility in explaining the relationship between CCBs and physical intimate partner violence (IPV). Australian women aged 18–68 years ( n = 739; Mage = 31.58, SDage = 11.76) completed an online survey. Count and frequency CCB approaches yielded similar significant associations with increased physical IPV. Both approaches suggest that frightening behaviors in particular are significantly indicative of also experiencing physical IPV; however, when you count CCB types, public name-calling becomes important, whereas when you examine the frequency of each CCB type, jealousy/possessiveness becomes important. These findings suggest differential utility between measures of CCBs, which examine the frequency of specific CCB types and which count CCB types, and that both approaches are useful in understanding how coercion and control relate to physical violence within intimate relationships.

The Travels of a Set of Numbers: The Multiple Networks Enabled by the Colombian ‘Estrato’ System

This article documents how a Constitutionally grounded effort to institute ‘cross subsidies’ for public utility payments gave rise to a set of numbers that never achieved the goal of cross-class solidarity. This legal based system lived on, in large part because the numbers were quickly adopted both in popular speech and by multiple institutions, in an uncoordinated manner. Scalar tensions are key to the story: the Colombian ‘estrato’ system for classifying residential properties (initially for differential utility payment purposes) has at its core a set of numbers that was designed as nationally valid: but the work of labelling all residences with one of the six numbers to produce zoning-like ‘estrato’ maps incites qualitative micro-local knowledge. Overall, we show that local knowledges of socioeconomic difference constantly clash with and undermine not only the initial ambitious plan to render cross-class ‘solidarity’ technical but also the subsequent efforts to propose more rational alternatives.

Orbitofrontal cortex neurons code utility changes during natural reward consumption as correlates of relative reward-specific satiety

Natural, on-going reward consumption can differentially reduce the subjective value (‘utility’) of specific rewards, which indicates relative, reward-specific satiety. Two-dimensional choice indifference curves (IC) represent the utility of choice options with two distinct reward components (‘bundles’) according to Revealed Preference Theory. We estimated two-dimensional ICs from stochastic choices and found that natural on-going consumption of two bundle rewards induced specific IC distortions that indicated differential reduction of reward utility indicative of relative reward-specific satiety. Licking changes confirmed satiety in a mechanism-independent manner. Neuronal signals in orbitofrontal cortex (OFC) that coded the value of the chosen option followed closely the consumption-induced IC distortions within recording periods of individual neurons. A neuronal classifier predicted well the changed utility inferred from the altered behavioral choices. Neuronal signals for more conventional single-reward choice options showed similar relationships to utility alterations from on-going consumption. These results demonstrate a neuronal substrate for the differential, reward-specific alteration of utility by on-going reward consumption reflecting reward-specific satiety.SignificanceRepeated delivery reduces the subjective value (‘utility’) of rewards to different degrees depending on their individual properties, a phenomenon commonly referred to as sensory-specific satiety. We tested monkeys during economic choice of two-component options. On-going consumption differentially reduced reward utility in a way that suggested relative reward-specific satiety between the two components. Neurons in the orbitofrontal cortex (OFC) changed their responses in close correspondence to the differential utility reduction, thus representing a neuronal correlate of relative reward-specific satiety. Control experiments with conventional single-component choice showed similar satiety-induced differential response reductions. These results are compatible with the notion of OFC neurons coding crucial decision variables robustly across different satiety levels.