Untested Assumptions Research Articles

Recent advances, misconceptions, untested assumptions, and future research agenda for identity fusion theory

AbstractJust a decade ago, two psychologists, Swann, and Gómez, developed a new theoretical framework to explain extreme pro‐group behaviors: identity fusion theory. Identity fusion refers to a visceral feeling of oneness with a group that motivates individuals to do extraordinary self‐sacrifices on behalf of the group or each of its members. Since the formulation of the theory, interdisciplinary researchers of the five continents have conducted dozens of studies on identity fusion, both in laboratory and field settings. Research has deepened into the causes, consequences, underlying mechanisms, and applications of identity fusion. The development of fusion‐based research has been steadfast and very prolific. Hence, the first section of the current manuscript includes an updated overview of this fast growing literature. This increasing interest for the theory has, however, been accompanied by a series of misconceptions and untested research assumptions, which we address in the second and third sections of the paper, concluding with a final section suggesting a future research agenda. Our aim is to help those interested in knowing more about identity fusion or about the causal mechanisms that lead individuals to risk their life and personal well‐being for a group discarding common misconceptions as well as formulating more precise and nuanced hypotheses for future research.

A Data-Informed Approach for Identifying Move-on Encounter Thresholds for Vulnerable Marine Ecosystem Indicator Taxa

The United Nations General Assembly has called for the adoption of conservation management measures to protect vulnerable marine ecosystems (VMEs) from significant adverse impacts outside of areas of national jurisdiction. In response, many regional fisheries management organisations (RFMOs) have implemented move-on rules triggered by encounter threshold levels for the biomass of VME indicator taxa retained as bycatch. However, due to uncertainty of the relationships between catch, catch efficiency and the in-situ biomass of VME indicator taxa, move-on rules alone may not be enough to prevent significant adverse impacts on VMEs. Although spatial management measures present one possible solution to these concerns, a lack of empirical data on the distribution of VMEs within the high seas means spatial management is often informed by model predictions of the spatial distribution of VME indicator taxa. Given the uncertainty associated with predicted distributions, move-on rules can provide immediate responses when spatial management measures may not be providing the expected conservation benefits. Using bycatch data from 9,771 New Zealand bottom trawls within the South Pacific RFMO Convention Area, we illustrate a data-informed approach for selecting high move-on encounter thresholds that may suggest the predicted distributions of VME taxa used to underpin spatial management are highly inaccurate. The reasoning that high thresholds act as a safeguard against uncertainty in the performance of spatial management measures requires untested assumptions regarding the level of permissible bycatch before further management action is required, with the acceptance of those assumptions a management decision balancing the sensitivity of the move-on rule with uncertainty regarding the effectives of the spatial management measures. Additional work is required to support these management decisions, including the determination of taxa-specific catchability estimates, and the seafloor density/biomass of VME indicator taxa that represents a VME. Obtaining this information will allow for the identification of encounter thresholds that are more ecologically meaningful. In the interim, the choice of thresholds should be re-evaluated as more experience with their application is gathered.

The Piney Branch site (District of Columbia, U.S.A.) and the significance of the quarry-refuse model for the interpretation of lithics sites

In the 1870s the amateur archaeologist Dr Charles Abbott discovered roughly-flaked bifacial artefacts that he called “paleoliths” near Trenton, New Jersey, which he claimed were artefact types similar to Lower Palaeolithic handaxes being found in western Europe at that time. This interpretation gave rise to what has been called the Great Palaeolithic War, a debate in the United States about the existence of an “American Palaeolithic” that only ended in 1890 when the archaeologist William H. Holmes from the Smithsonian Institution excavated the Piney Branch lithics site in Washington D.C.. On the basis of the bifacial reduction sequence that he reconstructed from the lithics excavated at Piney Branch, Holmes argued that any resemblance of paleoliths to Lower Palaeolithic handaxes was accidental. Holmes believed that paleoliths were discarded elements from the sequential reduction of stone nodules (which he called the “Progressive Series”) by recent American Indian knappers during the manufacture of projectile points. In other words, the Trenton paleoliths, and by implication similar roughly-flaked bifaces, were nothing more than quarry refuse (or “waste”). Since Holmes’ day the quarry-refuse model for the interpretation of large roughly-flaked bifacial implements as “waste” and not artefact types used in other activities, particularly for lithics sties in the arid western regions of the US, has been applied at times without adequate bridging arguments. A review of Holmes’ interpretation of the Piney Branch evidence suggests that his quarry-refuse model, even when applied to Piney Branch, required numerous untested assumptions, and that the model may inadvertently obscure a range of other prehistoric activities not strictly related to quarrying and knapping. As a consequence, the application of the quarry-refuse model today to lithics sites found in North America without careful examination may also fail to identify the complete range of cultural activity at those sites, and should be applied to lithics sites only with due caution and the testing of alternative hypotheses.

Does Trust in Government Increase Support for Redistribution? Evidence from Randomized Survey Experiments

Why have decades of high and rising inequality in the United States not increased public support for redistribution? An established theory in political science holds that Americans’ distrust of government decreases their support for redistribution, but empirical support draws primarily on regression analyses of national surveys. I discuss the untestable assumptions required for identification with regression modeling and propose an alternative design that uses randomized experiments about political corruption to identify the effect of trust in government on support for redistribution under weaker assumptions. I apply this to three survey experiments and estimate the effects that large, experimentally induced increases in political trust have on support for redistribution. Contrary to theoretical predictions, estimated effects are substantively negligible, statistically indistinguishable from zero, and comparable to estimates from two placebo experiments. I discuss implications for theory building about causes of support for redistribution in an era of rising inequality and eroding confidence in government.

The Ties that Bind Us: The Influence of Perceived State Similarity on Policy Diffusion

In this paper, we propose a new measure to understand policy connections between the states. For decades, diffusion scholars have relied on the largely untested assumption that contiguous states are more similar than noncontiguous states, despite evidence that similarity is more complex than geographic proximity. We use a unique survey of citizens’ perceptions of other states to construct a national network of similarity ties between the states. We apply this new measure with a data set of state policy adoptions in a dyadic and monadic event history analysis and find that similar state adoptions are a reliable predictor of policy innovation. We argue that perceived state similarity is a more complete measure of how states look to each other than contiguity.

A Likelihood-Based Approach for the Analysis of Longitudinal Clinical Trials with Return-to-Baseline Imputation

Discontinuation of assigned therapy in longitudinal clinical trials is often inevitable due to various reasons such as intolerability or lack of efficacy. When the primary outcome of interest is the mean difference between treatment groups at the end of the trial, how to deal with the missing data due to discontinuation of assigned therapy is critical. The draft ICH E9 (R1) addendum proposes several strategies for handling intercurrent events, such as discontinuation of assigned therapy, under the estimand framework. The “hypothetical strategy”, in which the outcomes after discontinuation are envisioned under the hypothetical condition that patients who discontinued assigned therapy had actually stayed on assigned therapy, is commonly employed but requires untestable assumptions about the distribution of the post-discontinuation data. Return-to-baseline (RTB) is an assumption recently suggested by at least one regulatory agency. RTB assumes that any treatment effects observed prior to discontinuation are washed out, such that the mean effect at the end of the study among discontinued patients is the same as that at baseline. Multiple imputation (MI) may be used to implement this method but may overestimate the variance. In this paper, we propose a likelihood-based method to get the point estimate and variance for the treatment difference directly from a mixed-model for repeated measures (MMRM) analysis. Simulations are conducted to evaluate its performance as compared to other approaches including MI and MI with bootstrap. Two clinical trials are used to demonstrate the application.

Estimating treatment effects under untestable assumptions with nonignorable missing data.

Nonignorable missing data poses key challenges for estimating treatment effects because the substantive model may not be identifiable without imposing further assumptions. For example, the Heckman selection model has been widely used for handling nonignorable missing data but requires the study to make correct assumptions, both about the joint distribution of the missingness and outcome and that there is a valid exclusion restriction. Recent studies have revisited how alternative selection model approaches, for example estimated by multiple imputation (MI) and maximum likelihood, relate to Heckman-type approaches in addressing the first hurdle. However, the extent to which these different selection models rely on the exclusion restriction assumption with nonignorable missing data is unclear. Motivated by an interventional study (REFLUX) with nonignorable missing outcome data in half of the sample, this article critically examines the role of the exclusion restriction in Heckman, MI, and full-likelihood selection models when addressing nonignorability. We explore the implications of the different methodological choices concerning the exclusion restriction for relative bias and root-mean-squared error in estimating treatment effects. We find that the relative performance of the methods differs in practically important ways according to the relevance and strength of the exclusion restriction. The full-likelihood approach is less sensitive to alternative assumptions about the exclusion restriction than Heckman-type models and appears an appropriate method for handling nonignorable missing data. We illustrate the implications of method choice for inference in the REFLUX study, which evaluates the effect of laparoscopic surgery on long-term quality of life for patients with gastro-oseophageal reflux disease.

Identification of Causal Direct-Indirect Effects Without Untestable Assumptions

In causal mediation analysis, identification of existing causal direct or indirect effects requires untestable assumptions in which potential outcomes and potential mediators are independent. This paper defines a new causal direct and indirect effect that does not require the untestable assumptions. We show that the proposed measure is identifiable from the observed data, even if potential outcomes and potential mediators are dependent, while the existing natural direct or indirect effects may find a pseudo-indirect effect when the untestable assumptions are violated.

Teachers Are: Analyzing the Metaphors of Pre-Service Educators

Metaphors are often used by in-service educators to describe themselves and their work in the classroom. These metaphors can articulate in-service teachers’ fundamental dispositions and provide the vehicle for conceptualizing teaching practices. Pre-service educators (those engaged in preparation to enter the teaching vocation), however, are a different population for whom metaphors represent relatively untested assumptions about the classroom and the practices that pervade it. These metaphors should be considered an asset which, if effectively utilized, can aid in the work of teacher preparation. To that end, this study employed the Conceptual Metaphor Theory of Lakoff & Johnson (1980) within the propositional analysis framework of Steen (1999) to provide a generalizable approach to metaphor analysis that could be used in educator preparation programs.

Keep the books on the shelves: Library space as intrinsic facilitator of the reading experience

Library literature frequently reports projects to remove print collections and replace them with other amenities for patrons. This project challenges the untested assumption that the physical library itself serves no useful function to its users unless they are actively consulting books from the shelves. The alternative hypothesis is that readers benefit from the mere act of studying while in a book-filled environment.To test this possibility, ten subjects completed SAT-style reading comprehension tests in both a traditional library environment, and a renovated chapel that strongly resembles library space except for lacking books. Results provide a reasonable basis to support an expectation that readers perform better on reading comprehension tasks performed in book-rich environments.

Characterizing the Validity and Real-World Utility of Health Technology Assessments in Healthcare: Future Directions Comment on "Problems and Promises of Health Technologies: The Role of Early Health Economic Modelling".

With their article, Grutters et al raise an important question: What do successful health technology assessments (HTAs) look like, and what is their real-world utility in decision-making? While many HTAs are published in peer-reviewed journals, many are considered proprietary and their attributes remain confidential, limiting researchers’ ability to answer these questions. Models for economic evaluations like cost-effectiveness analyses (CEAs) synthesize a wide range of evidence, are often statistically and mathematically sophisticated, and require untestable assumptions. As such, there is nearly universal agreement among researchers that enhancing transparency is an important issue in health economic modeling. However, the definition of transparency and guidelines for its implementation vary. Model registration combined with a linked database of model-based economic evaluations has been proposed as a solution, whereby registered models and their accompanying technical and nontechnical documentation are sourced into a single publicly-available repository, ideally in a standardized format to ensure consistent and complete representation of features, code, data sources, results, validation exercises, and policy recommendations. When such a repository is ultimately created, modelers will not have to reinvent the wheel for every new drug launched or new treatment pathway. These more open and transparent approaches will have substantial implications for model accuracy, reliability, and validity, improving trust and acceptance by healthcare decision-makers.

Scale-dependent co-occurrence patterns of closely related genotypes in a lichen species complex

AbstractThe ‘competition-relatedness’ hypothesis postulates that co-occurring taxa should be more distantly related, because of lower competition. This hypothesis has been criticized for its dependence on untested assumptions and its exclusion of other assembly forces beyond competition and habitat filtering to explain the co-existence of closely related taxa. Here we analyzed the patterns of co-occurring individuals of lichenized fungi in theGraphis scriptacomplex, a monophyletic group of species occurring in temperate forests throughout the Northern Hemisphere. We generated sequences for three nuclear ribosomal and protein markers (nuLSU,RPB2,EF-1) and combined them with previously generated sequences to reconstruct an updated phylogeny for the complex. The resulting phylogeny was used to determine the patterns of co-occurrences at regional and at sample (tree) scales by calculating standard effect size of mean pairwise distance (SES.MPD) among co-occurring samples to determine whether they were more clustered than expected from chance. The resulting phylogeny revealed multiple distinct lineages, suggesting the presence of several phylogenetic species in this complex. At the regional and local (site) levels, SES.MPD exhibited significant clustering for five out of six regions. The sample (tree) scale SES. MPD values also suggested some clustering but the corresponding metrics did not deviate significantly from the null expectation. The differences in the SES.MPD values and their significance indicated that habitat filtering and/or local diversification may be operating at the regional level, while the local assemblies on each tree are interpreted as being the result of local competition or random colonization.

The use of Administrative Data to combat non-response

Background The issues arising due to participant non-response are problematic for many surveys. An international trend of falling survey response rates has led to more researchers questioning the extent to which non-response can cause issues with analysis, and what can be done to combat this non-response. Non-response weighting is a common method used by surveys, however the construction of these weights can rely upon untested assumptions and low quality and quantity of data. Administrative data can provide new opportunities in survey design, including improved construction of non-response weights, allowing better survey-based estimates.
 Main Aim In this paper we explore the potential of using administrative data from the sampling frame of a large social survey to model non-response. The data used for this paper is part of the Healthy Aging in Scotland (HAGIS) Survey.
 Methods The HAGIS pilot wave collected a sample of approximately 1000 individuals aged over 50 in the Scottish mainland. HAGIS utilised administrative data in the sampling with screening being provided to select households with at least one eligible respondent (over 50). Administrative data were also available for the full sample, and not just respondents to the HAGIS pilot wave. The administrative data consists of individual demographics, hospital admissions, and prescription data held by NHS Scotland.
 Results Survey response is modelled as a function of explanatory variables from the administrative data in order to examine whether there is systematic demographic and health-based non-response in the survey. We further examine whether this non-response is causing significant biases and then how health data might predict non-response.
 Conclusion Finally, we discuss how these models could be used in improving conventional weighting techniques to combat non-response in survey design.

The Reception by Domestic Courts of the Res Interpretata Effect of Jurisprudence of the European Court of Human Rights

Abstract This article focuses on two subjects: the attitude of national courts towards the jurisprudence of the European Court of Human Rights and their role in the achievement of effective domestic implementation of the European Convention on Human Rights. The first topic outlines a typology of the positions adopted, which is proposed in order to underline the national strategies regarding the reception of the res interpretata effect of the Court’s judgments. The second provides a critical analysis of the mirror metaphor, which is proposed to resolve some unproven and untested assumptions that domestic courts act as puppets and cannot go beyond Convention standards without violating the Court’s authentic interpretations. In both cases, examples are given of domestic courts’ practices in order to clarify that the judicial interaction between domestic courts and the European Court of Human Rights is not always harmonious.

USE OF EXPOSURE CROSSOVER DESIGN TO CONTROL FOR UNMEASURED BASELINE CONFOUNDING IN OBSERVATIONAL STUDIES

Observational comparative effectiveness studies face the challenge of selection bias. Due to lack of randomization, an alleged treatment effect may reflect inherent differences in baseline characteristics between comparison groups, rather than the outcome of treatment. Propensity score methods were devised to “resample” a most comparable comparison group, under a strong yet untestable assumption of no unmeasured confounding. We present an “exposure crossover” study evaluating complementary and integrative health approaches (CIH) among 6,379 US veterans who received acupuncture, massage or chiropractic therapies between 10/1/2011-9/30/2013. Their average pain intensity ratings (PIRs) during the 12-months after CIH initiation (effect period, EP) were compared with the 12-months before (baseline period, BP). Through this built-in self-matching, veterans’ characteristics and other stable baseline confounding, measured and unmeasured, were presumably eliminated. After accounting for time-varying opioid use and within-subject correlations using a generalized estimating equation, we found that in comparison to the BP, the adjusted mean PIR during the EP was -0.40 (95% Confidence Interval (CI): -0.51, -0.29) points lower; while the adjusted rate ratio of moderate to severe pain (PIRs ≥ 4) was 34% lower [0.66 (95% CI: 0.62, 0.70)]. The effect sizes were greater among veterans older than 65 years, yet diminished to null after 6-9 months. Assuming a 3-month induction period, using alternative random-intercept model, and examining post-CIH opioid use as an alternative outcome, derived similar results. These observations echo some randomized trials suggesting a modest, short-term CIH benefit, and highlight the merits and usefulness of exposure-crossover design to observational studies of medical interventions.

Chemistry of ion injection in supernova remnant shocks: hybrid simulations in the light of He/C/O data from AMS-02

The high precision spectrometry of galactic cosmic rays (CR), e.g. PAMELA experiment [1], accurately determined an approximately 0.1 difference between the rigidity spectral indices of protons and He ions. Similar deviations have been indicated earlier by other experiments [2] confirmed by the recent high-fidelity AMS-02 measurements [3]. These findings widen the window into a complicated selection process whereby collisionless shocks, such as supernova remnant (SNR) blast waves, extract different chemical elements from an interstellar matter mix. The similarity of He/p, C/p, and O/p rigidity spectra demonstrated by AMS-02 has provided new evidence that injection is a mass-to-charge (A/Z) dependent process. We investigate the particle injection into the diffusive shock acceleration using one- and two-dimensional self-consistent hybrid simulations. Our 1D simulations prove that an SNR shock can modify the chemical composition of accelerated CRs by preferentially extracting them from a homogeneous background plasma without additional, largely untestable assumptions. Our results confirm the earlier theoretical predictions of how the efficiency of injection depends on the shock Mach number MA. They show that selection rate of different ion species increases with A/Z, saturates, and peaks as a function of MA. The 2D simulations also evidence a deviation from the linear selection rate vs A/Z trend, pointing towards a saturation for higher A/Z. The integrated SNR rigidity spectrum for proton-to-helium flux ratio, obtained by the convolution of the time-dependent injection rates of protons and He ions with a decreasing shock strength over the active lives of SNRs, compares well with the AMS-02 and PAMELA data. The numerical results [4] correctly predict the decrease in p/He flux ratio with increasing rigidity at exactly the rate measured in the experiments for ℜ > 10 GV. Only at lower rigidities, ℜ < 10 GV, the difference between the data and our predictions becomes noticeable. Whether this deviation comes from the propagation through the interstellar medium or solar modulation, remains unclear. Except for this uncertainty, the suggested mechanism for A/Z-dependence of the injection fully explains the measured p/He ratio.

Direct Observation of Nanoparticulate Goethite Recrystallization by Atom Probe Analysis of Isotopic Tracers

Goethite (α-FeOOH) is dispersed throughout the earth's surface, and its propensity to recrystallize in aqueous solutions determines whether this mineral is a source or sink for critical trace elements in the environment. Under reducing conditions, goethite commonly coexists with aqueous Fe(II) (Fe(II)aq), which accelerates recrystallization by coupled electron transfer and atom exchange. Quantifying the amount of the mineral phase that exchanges its structural Fe(III) atoms with Fe(II)aq is complicated by recrystallization models with untested assumptions of whether, and to what extent, the recrystallized portion of the mineral continues to interact with the solution. Here, we reacted nanoparticulate goethite with 57Fe-enriched Fe(II)aq and used atom probe tomography (APT) to resolve the three-dimensional distribution of Fe isotopes in goethite at the sub nm scale. We found that the 57Fe tracer isotope is enriched in the bulk structure (tens of nanometers deep), with some samples having 57Fe penetration throughout at a level that is similar to the isotopic composition of Fe(II)aq. This suggests that some particles undergo near-complete recrystallization. In other cases, however, the distribution of 57Fe is more heterogeneous and generally concentrates near the particle periphery. Nanoparticle encapsulation and subsequent APT can hence capture hidden recrystallization mechanisms which are critical to predicting mineral reactivity in aqueous solutions.

O brother how art thou: Propensity to report self-assessed unmet need

Research investigating self-assessed unmet need (SUN) has taken the reports from surveys as given and subsequently attempted to discover patterns in inequality of access to healthcare. This requires the yet untested assumption that, given a certain level of care and demand, the likelihood of reporting unmet need does not vary across socioeconomic/demographic status (SEDS), be satisfied. Using an administrative dataset spanning 2001 to 2011 comprised of sufferers of a set of conditions that suggest unmet need (n = 3300) we evaluate the proposition that, given health status and care received, the propensity to report unmet need does not vary along SEDS. The results are further validated using the Canadian Community Health Surveys between 2001 and 2013 (n = 237,483). We find that the assumption of independence between reporting SUN and SEDS is not satisfied. Many of the groups found to have less access in previous studies may simply be more prone to interpret/answer the survey questions about unmet need in a certain way. The results of this research suggest that, in its present incarnation, survey data on self-assessed unmet need does not accurately measure what much of the academic literature has assumed it does.

A Theory of Arts Entrepreneurship as Organizational Attack

Arguably, both success and failure in arts entrepreneurship do not depend upon one’s own ability to employ themselves or create a business. Given that the academic field of arts entrepreneurship is still emerging, it is not surprising that arts entrepreneurship theory is underdeveloped. While a theory of arts entrepreneurship could help answer the recurring question (i.e., What is arts entrepreneurship?), without a theory supported by evidence, what arts entrepreneurship “is” may be based on individual subjectivity, discipline-based bias, and untested assumptions. To address this gap in the arts entrepreneurship literature, I propose a theory of arts entrepreneurship evidenced by repeated observations that are verifiable via case study experiences.

Compensation and Compliance: Sources of Public Acceptance of the U.K. Supreme Court's Brexit Decision

The perception that a high court's decision is binding and final is a crucial prerequisite for its ability to settle political conflicts. Under what conditions are citizens more likely to accept controversial judicial rulings? Mass acceptance is determined, in part, by how rulings are framed during public debate. This paper takes a broad view of the strategies and actors that influence the discursive environment surrounding judgments, calling attention to hitherto unexamined determinants of mass acceptance. We theorize that third parties can boost acceptance by pledging compliance, and that courts can moderate opposition by compensating losers. We also look at how populist attacks on judiciaries, common in contemporary democracies, affect acceptance. We test these propositions using a survey experiment conducted in the aftermath of the UK Supreme Court's Brexit decision, the most salient judgment handed down by this court to date. The paper moves the literature on courts and public opinion beyond the United States, and presents evidence backing largely untested assumptions at the heart of models of judicial behavior regarding the benefits of crafting rulings with an eye on the preferences of key audiences.