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In the age of post-neoliberal globalization, complex interdependence has resulted in the integration of many economies and the industries within them and led to varied national and subnational political and economic responses. These forces have enabled the rise of a new political economy that requires the contextualized comparative sector approach (CCSA). This article advances a research agenda that contends theoretical and empirical leverage for explaining heterogeneity and assessing generalizability is gained by taking contextualized comparisons to the sector level of analysis. The CCSA identifies the multidimensional effects of sectors, uncovering new sites of inquiry connected to sectoral structural attributes, context-specific sectoral organization of institutions, and social and political constructions of sectors. Sectors are thus contexts that are embedded in multilevel contexts involving state and nonstate actors alike. Scholarship on industrial policy, technology and innovation, environmental transition, and regulation and governance demonstrates the analytical power and theoretical value of combining contextualized comparisons and sectoral analysis, which have been overlooked by the overly macro- or micro-level studies dominant in international and comparative political economy. The various strategies of the approach and a stepwise discussion of a research design underscore the possibilities for theory development and testing, adjudication of competing explanations, and case-specific discoveries.
Most cognitive studies of bipolar disorder (BD) have examined case–control differences on cognitive tests using measures of central tendency, which do not consider intraindividual variability (IIV); a distinct cognitive construct that reliably indexes meaningful cognitive differences between individuals. In this study, we sought to characterize IIV in BD by examining whether it differs from healthy controls (HCs) and is associated with other cognitive measures, clinical variables, and white matter microstructure.
Methods
Two hundred and seventeen adults, including 100 BD outpatients and 117 HCs, completed processing speed, sustained attention, working memory, and executive function tasks. A subsample of 55 BD participants underwent diffusion tensor imaging. IIV was operationalized as the individual standard deviation in reaction time on the Continuous Performance Test-Identical Pairs version.
Results
BD participants had significantly increased IIV compared to age-matched controls. Increased IIV was associated with poorer mean performance scores on processing speed, sustained attention, working memory, and executive function tasks, as well as two whole-brain white matter indices: fractional anisotropy and radial diffusivity.
Conclusions
IIV is increased in BD and appears to correlate with other cognitive variables, as well as white matter measures that index reduced structural integrity and demyelination. Thus, IIV may represent a neurobiologically informative cognitive measure for BD research that is worthy of further investigation.
This chapter introduces a new model to represent the heterogeneity of the Italian civitates. The model is based on the abundant archaeological evidence of the inhabited areas of their administrative centres, using it as a proxy for various economic and socio-political aspects of the civitas. This new variation model surpasses previous ones by being continuous (rather than categorical) and by formally incorporating the uncertainties associated with missing data.
Major depressive disorder (MDD) is a complex and heterogeneous disorder, and this heterogeneity poses a significant challenge for advancing precision medicine in patients with MDD. MRI-based subtyping analysis has been widely employed to address the heterogeneity of MDD patients. In this study, we investigated the subtypes of first-episode and drug-naive (FEDN) MDD patients based on the individualized structural covariance network (IDSCN).
Methods
In this study, we used T1-weighted anatomical images of 164 FEDN MDD patients and 164 healthy controls from the REST-meta-MDD consortium. The IDSCN of participants was obtained using the network template perturbation method. Subtypes of FEDN MDD were identified using k-means clustering analysis, and differences in neuroimaging findings and clinical symptoms between the identified subtypes were compared using two-sample t-tests.
Results
This study identified two subtypes of FEDN MDD: subtype 1 (n = 117) and subtype 2 (n = 47) by characterizing 10 edges that were significantly altered in at least 5% of patients (i.e., 8 patients) in the IDSCN. Compared with subtype 2, subtype 1 had significantly higher anxiety symptom scores, stronger structural covariance edges in 9 edges within the thalamus, and a significantly reduced gray matter volume (GMV) in the frontal and parietal regions, and in the thalamus.
Conclusions
Our results suggest that patients with FEDN MDD can be classified into two different subtypes based on their IDSCN, providing an important reference for personalized treatment and precision medicine for patients with FEDN MDD.
Model-based recursive partitioning (MOB) and its extension, metaMOB, are tools for identifying subgroups with differential treatment effects. When pooling data from various trials the metaMOB approach uses random effects to model the heterogeneity of treatment effects. In situations where interventions offer only small overall benefits and require extensive, costly trials with a large participant enrollment, leveraging individual-participant data (IPD) from multiple trials can help identify individuals who are most likely to benefit from the intervention. We explore the application of MOB and metaMOB in the context of non-specific low back pain treatment, using synthetic data based on a subset of the individual participant data meta-analysis by Patel et al.1 Our study underscores the need to explore heterogeneity in intercepts and treatment effects to identify subgroups with differential treatment effects in IPD meta-analyses.
P-value functions are modern statistical tools that unify effect estimation and hypothesis testing and can provide alternative point and interval estimates compared to standard meta-analysis methods, using any of the many p-value combination procedures available (Xie et al., 2011, JASA). We provide a systematic comparison of different combination procedures, both from a theoretical perspective and through simulation. We show that many prominent p-value combination methods (e.g. Fisher’s method) are not invariant to the orientation of the underlying one-sided p-values. Only Edgington’s method, a lesser-known combination method based on the sum of p-values, is orientation-invariant and still provides confidence intervals not restricted to be symmetric around the point estimate. Adjustments for heterogeneity can also be made and results from a simulation study indicate that Edgington’s method can compete with more standard meta-analytic methods.
We provide a unified theory, within the framework of the multi-phase Darcy description, on gravity current, interfacial and unsaturated flows in a vertically heterogeneous porous layer, which finds applications in many geophysical, environmental and industrial contexts. Based on the assumption of vertical gravitational-capillary equilibrium, a theoretical model is presented to describe the time evolution of the saturation field and the interface shape, imposing a general formula for the vertical distribution of intrinsic permeability, porosity and capillary entry pressure. Example calculations are then provided in the Cartesian configuration to illustrate potential implications of the theory, imposing power-law distribution of vertical heterogeneity. Seven dimensionless parameters are identified, which arise from the standard Darcy description of multi-phase flow and measure the influence of vertical heterogeneity, viscosity ratio, and the competition between gravitational and capillary forces. Four asymptotic regimes are recognised, representing unconfined unsaturated flows, confined unsaturated flows, unconfined interfacial flows and confined interfacial flows. The influence of heterogeneity is then discussed in the two unsaturated flow regimes based on the evolution of the interface shape, frontal location, saturation distribution, and the time transition between unconfined and confined self-similar flows.
Species abundances and richness are central parameters in ecology and crucial for describing diversity and composition across environments. Understanding how they vary in natural environments is critical for informed conservation decisions, especially in the face of anthropogenic pressures, such as deforestation and climate change. We evaluate the influence of landscape and local habitat variables on the richness and abundances of lizards in the Caatinga, the largest continuous block of seasonally dry tropical forests. We sampled seven lizard communities for three months using visual encounters along transects. We recorded landscape and microhabitat variables and evaluated their influence on lizard species richness, diversity, and occurrence using model selection. Ten lizard species were recorded, with Tropidurus semitaeniatus, Ameivula ocellifera, and Tropidurus hispidus being the most abundant. Topographic complexity and the number of rocky outcrops positively affect species richness and diversity by promoting environmental heterogeneity and hence increasing refuges, shelters, and thermoregulation sites. Different microhabitat and landscape variables were important predictors of the occurrences of individual lizard species. The quantity of rocks significantly increased the likelihood of Tropidurus semitaeniatus occurrence, while litter negatively affected Tropidurus hispidus, and fallen logs increased the probability of Ameiva ameiva occurrence. We argue that preserving topographically complex regions is essential for maintaining the diversity of lizards in the Caatinga biome.
Using public goods games in a laboratory setting, we study team-level production, where two teams compete for the resources of a common-member who can benefit from and provide effort in both teams. Intrinsically, the common-member faces divided loyalties. We examine such competition in a setting in which the common-member has productive abilities equal to that of the other team members (dedicated-members), and in two settings where he/she has greater relative potential. When effort (contributions) by the common-member have greater productivity (coupled with higher opportunity costs to contribute) in providing the public good relative to that of dedicated-members, we find team performance is not significantly increased. On the other hand, when the common-member has a greater endowment, sufficient to match the absolute contributions of team members in both teams, there is a significant increase in team performance. The evidence suggests that a norm of reciprocity by dedicated-members based on absolute contributions of the common-member better explains behavior than a norm based on the value added of the common-member's contributions. This behavior, along with fairness norms elicited in a survey, suggests that on average dedicated members do not sufficiently incorporate the common-members' higher opportunity costs in the treatment where his/her productivity is increased. This setting provides an important illustration of where the behavioral response to the type of inequality matters, leading to differences in team efficiency.
Autism spectrum disorder is defined by the presence of sustained problems in areas of social cognition and social understanding alongside repetitive and/or restricted patterns of behaviour. Behavioural presentations and developmental trajectories in autism are highly heterogeneous. For most, characteristics variably continue across the lifespan, and, for many, they overlap with numerous overrepresented comorbid combinations spanning behavioural, psychiatric and somatic domains. The current autism diagnostic systems (DSM-5, ICD-11) reflect this heterogeneity, focusing on discerning different assistance needs and symptom severity combinations. An emerging view on the pluralisation of autism – ‘the autisms’ – based on different severity levels and different developmental trajectories is gaining popularity, bolstered by the introduction of the grouping ‘profound autism’ and observations of non-persistence of autism for some. We advance the case for expanding the definition of the plural autisms based also on the numerous different aetiological routes that can lead to autism. Various genetic conditions, susceptibility to infectious agents, non-infectious environmental exposures and immune-mediated occurrences have all been observed to culminate in a diagnosis of autism. As a triad, aetiology, presentation intensity and developmental trajectory offer new ways to classify the autisms, with potentially important implications for research and practice.
Experiments on saving behavior reveal substantial heterogeneity of behavior and performance. We show that this heterogeneity is reliable and examine several potential sources of it, including cognitive ability and personality scales. The strongest predictors of both behavior and performance are two cognitive ability measures. We conclude that complete explanations of heterogeneity in dynamic decision making require attention to complexity and individual differences in cognitive constraints.
Norm-based accounts of social behavior in economics typically reflect tradeoffs between maximization of own consumption utility and conformity to social norms. Theories of norm-following tend to assume that there exists a single, stable, commonly known injunctive social norm for a given choice setting and that each person has a stable propensity to follow social norms. We collect panel data on 1468 participants aged 11–15 years in Belfast, Northern Ireland and Bogotá, Colombia in which we measure norms for the dictator game and norm-following propensity twice at 10 weeks apart. We test these basic assumptions and find that norm-following propensity is stable, on average, but reported norms show evidence of change. We find that individual-level variation in reported norms between people and within people across time has interpretable structure using a series of latent transition analyses (LTA) which extend latent class models to a panel setting. The best fitting model includes five latent classes corresponding to five sets of normative beliefs that can be interpreted in terms of what respondents view as “appropriate” (e.g. equality vs. generosity) and how they view deviations (e.g. deontological vs. consequentialist). We also show that a major predictor of changing latent classes over time comes from dissimilarity to others in one’s network. Our application of LTA demonstrates how researchers can engage with heterogeneity in normative perceptions by identifying latent classes of beliefs and deepening understanding of the extent to which norms are shared, stable, and can be predicted to change. Finally, we contribute to the nascent experimental literature on the economic behavior of children and adolescents.
There is ample evidence that people differ considerably in their preferences. We identify individual heterogeneity in type and strength of social preferences in a series of binary three-person dictator games. Based on this identification, we analyze response times in another series of games to investigate the cognitive processes of distributional preferences. We find that response time increases with the number of conflicts between individually relevant motives and decreases with the utility difference between choice options. The selfish motive is more intuitive for subjects who are more selfish. Our findings indicate that the sequential sampling process and the intuition of selfishness jointly produce distribution decisions, and provide an explanation for the mixed results on the correlations between response time and prosociality. Our results also show that it is important to take heterogeneity of preferences into account when investigating the cognitive processes of social decision making.
Competition between groups is ubiquitous in social and economic life, and typically occurs between groups that are not created equal. Here we experimentally investigate the implications of this general observation on the unfolding of symmetric and asymmetric competition between groups that are either homogeneous or heterogeneous in the ability of their members to contribute to the success of the group. Our main finding is that relative to the benchmark case in which two homogeneous compete against each other, heterogeneity within groups per se has no discernable effect on competition, while introducing heterogeneity between groups leads to a significant intensification of conflict as well as increased volatility, thereby reducing earnings of contest participants and increasing inequality. We further find that heterogeneous groups share the labor much more equally than predicted by theory, and that in asymmetric contests group members change the way in which they condition their efforts on those of their peers. Implications for contest designers are discussed.
Voluntary carbon markets present firms and individuals with the opportunity to offset all or part of their carbon footprints. We report on a controlled laboratory experiment to understand the behavioral motivations driving the purchase of carbon offsets, in addition to investigating the effect of the introduction of voluntary carbon markets on emission-causing activities. We find a stable demand for offsets when the price is sufficiently low. Behavior is, however, heterogeneous. Individuals with a high (low) personal-responsibility index increase their offset purchases as their own damage (total damages) increases, but do not condition their offsetting behavior on the total damages (own damage) generated. We also show that, when individuals trade in competitive markets, the availability of offsets does not affect the total damages generated. Introduction of carbon offsets increases individuals’ earnings by eliminating some of the damages ex-post, but does not increase economic efficiency.
We study learning and selection and their implications for possible effort escalation in a simple game of dynamic property rights conflict: a multi-stage contest with random resolve. Accounting for the empirically well-documented heterogeneity of behavioral motives of players in such games turns the interaction into a dynamic game of incomplete information. In contrast to the standard benchmark with complete information, the perfect Bayesian equilibrium features social projection and type-dependent escalation of efforts caused by learning. A corresponding experimental setup provides evidence for type heterogeneity, for belief formation and updating, for self-selection and for escalation of efforts in later stages.
Differences in cognitive sophistication and effort are at the root of behavioral heterogeneity in economics. To explain this heterogeneity, behavioral models assume that certain choices indicate higher cognitive effort. A fundamental problem with this approach is that observing a choice does not reveal how the choice is made, and hence choice data is insufficient to establish the link between cognitive effort and behavior. We show that deliberation times provide an individually-measurable correlate of cognitive effort. We test a model of heterogeneous cognitive depth, incorporating stylized facts from the psychophysical literature, which makes predictions on the relation between choices, cognitive effort, incentives, and deliberation times. We confirm the predicted relations experimentally in different kinds of games.
Psychological games of guilt aversion assume that preferences depend on (beliefs about) beliefs and on the guilt sensitivity of the decision-maker. We present an experiment designed to measure guilt sensitivities at the individual level for various stake sizes. We use the data to estimate a structural choice model that allows for heterogeneity, and permits that guilt sensitivities depend on stake size. We find substantial heterogeneity of guilt sensitivities in our population, with 60% of decision makers displaying stake-dependent guilt sensitivity. For these decision makers, we find that average guilt sensitivities are significantly different from zero for all stakes considered, while significantly decreasing with the level of stakes.
Previous research demonstrates that individuals vary in their social preferences. Less well-understood is how group composition affects the behavior of different social preference types. Does one bad apple really spoil the bunch? This paper exogenously identifies experimental participants’ social preferences, then systematically assigns individuals to homogeneous or heterogeneous groups to examine the impact of ‘bad apples’ on cooperation and efficiency. Consistent with previous research, we find that groups with more selfish types achieve lower levels of efficiency. We identify two mechanisms for the effect. First, the selfish players contribute less. Second, selfish players induce lower contributions from the conditional cooperators, and this effect increases in the number of selfish players. These results are not sensitive to information about the distribution of types in the group.
Major depressive disorder (MDD) is a heterogeneous condition characterized by significant intersubject variability in clinical presentations. Recent neuroimaging studies have indicated that MDD involves altered brain connectivity across widespread regions. However, the variability in abnormal connectivity among MDD patients remains understudied.
Methods
Utilizing a large, multi-site dataset comprising 1,276 patients with MDD and 1,104 matched healthy controls, this study aimed to investigate the intersubject variability of structural covariance (IVSC) and functional connectivity (IVFC) in MDD.
Results
Patients with MDD demonstrated higher IVSC in the precuneus and lingual gyrus, but lower IVSC in the medial frontal gyrus, calcarine, cuneus, and cerebellum anterior lobe. Conversely, they exhibited an overall increase in IVFC across almost the entire brain, including the middle frontal gyrus, anterior cingulate cortex, hippocampus, insula, striatum, and precuneus. Correlation and mediation analyses revealed that abnormal IVSC was positively correlated with gray matter atrophy and mediated the relationship between abnormal IVFC and gray matter atrophy. As the disease progressed, IVFC increased in the left striatum, insula, right lingual gyrus, posterior cingulate, and left calcarine. Pharmacotherapy significantly reduced IVFC in the right insula, superior temporal gyrus, and inferior parietal lobule. Furthermore, we found significant but distinct correlations between abnormal IVSC and IVFC and the distribution of neurotransmitter receptors, suggesting potential molecular underpinnings. Further analysis confirmed that abnormal patterns of IVSC and IVFC were reproducible and MDD specificity.
Conclusions
These results elucidate the heterogeneity of abnormal connectivity in MDD, underscoring the importance of addressing this heterogeneity in future research.