Self-selection Effects Research Articles

Self-selection effects and modulation of TaOx resistive switching random access memory with bottom electrode of highly doped Si

In this paper, we propose a TaOx resistive switching random access memory (RRAM) device with operation-polarity-dependent self-selection effect by introducing highly doped silicon (Si) electrode, which is promising for large-scale integration. It is observed that with highly doped Si as the bottom electrode (BE), the RRAM devices show non-linear (>103) I-V characteristic during negative Forming/Set operation and linear behavior during positive Forming/Set operation. The underling mechanisms for the linear and non-linear behaviors at low resistance states of the proposed device are extensively investigated by varying operation modes, different metal electrodes, and Si doping type. Experimental data and theoretical analysis demonstrate that the operation-polarity-dependent self-selection effect in our devices originates from the Schottky barrier between the TaOx layer and the interfacial SiOx formed by reaction between highly doped Si BE and immigrated oxygen ions in the conductive filament area.

Incorporating a multiple discrete-continuous outcome in the generalized heterogeneous data model: Application to residential self-selection effects analysis in an activity time-use behavior model

This paper makes both a methodological contribution as well as an empirical contribution. From a methodological perspective, we propose a new econometric approach for the estimation of joint mixed models that include a multiple discrete choice outcome and a nominal discrete outcome, in addition to the count, binary/ordinal outcomes, and continuous outcomes considered in traditional structural equation models. These outcomes are modeled together by specifying latent underlying unobserved individual lifestyle, personality, and attitudinal factors that impact the many outcomes, and generate the jointness among the outcomes. From an empirical perspective, we analyze residential location choice, household vehicle ownership choice, as well as time-use choices, and investigate the extent of association versus causality in the effects of residential density on activity participation and mobility choices. The sample for the empirical application is drawn from a travel survey conducted in the Puget Sound Region in 2014. The results show that residential density effects on activity participation and motorized auto ownership are both associative as well as causal, emphasizing that accounting for residential self-selection effects are not simply esoteric econometric pursuits, but can have important implications for land-use policy measures that focus on neo-urbanist design.

Viewpoint: Quantifying residential self-selection effects: A review of methods and findings from applications of propensity score and sample selection approaches

The phenomenon whereby individuals self-select into their residential environment based on previously determined preferences for how to travel is known as residential self-selection (RSS). Numerous studies have investigated the influence of RSS on the estimated effect of the built environment on travel behavior. However, surprisingly few have actually quantified its effect in terms of partitioning the total influence of the built environment (BE) on travel behavior into a component attributable to RSS and one attributable to the built environment itself. This paper reviews 10 analyses (found in seven studies) that have quantified the proportion of the total influence of the built environment that is due to the BE itself (which we call the BEP), using either propensity-score or sample-selection approaches to control for RSS. After first outlining the basics of each approach, we then explain the various methods used to compute the BEP, followed by a discussion of the empirical results. The estimated BEPs vary widely, ranging from 34 percent to 98 percent. A number of reasons for these disparities are suggested, but there is considerable divergence in estimates even when many of these factors are held constant. Additional research is called for to better understand the circumstances under which the BEP is higher or lower.

Does Economics and Business Education Wash Away Moral Judgment Competence?

In view of the numerous accounting and corporate scandals associated with various forms of moral misconduct and the recent financial crisis, economics and business programs are often accused of actively contributing to the amoral decision making of their graduates. It is argued that theories and ideas taught at universities engender moral misbehavior among some managers, as these theories mainly focus on the primacy of profit-maximization and typically neglect the ethical and moral dimensions of decision making. To investigate this criticism, two overlapping effects must be disentangled: the self-selection effect and the treatment effect. Drawing on the concept of moral judgment competence, we empirically examine this question with a sample of 1773 bachelor’s and 501 master’s students. Our results reveal that there is neither a self-selection nor a treatment effect for economics and business studies. Moreover, our results indicate that—regardless of the course of studies—university education in general does not seem to foster students’ moral development.

Learning from the FCC's Lifeline Broadband Pilot Projects

In 2013, the Federal Communications Commission facilitated 14 experimental broadband Lifeline projects proposed by wireline and wireless broadband providers around the country. The projects tested consumer responses to a range of issues, including preferences for speed, the effects of different levels and types of discounts, and the effectiveness of different methods of outreach. In order to focus on the unconnected, participants could not have subscribed to broadband service within the past 60 days. In practice, the vast majority of them had never had broadband.The most consistent result was unexpected: an extremely low participation rate. Wireline providers and mobile providers (except those in Puerto Rico) managed to sign up less than 10 percent of the number of participants they had expected despite extensive outreach efforts. Puerto Rico mobile providers met their participation goals probably because of mass-market television advertising. These results demonstrate the difficulty of encouraging low-income people without connections to sign up even with large discounts, suggesting that subsidies are likely to go to people who already subscribe rather than working to close the digital divide.The trials also revealed subscribers’ willingness to trade off speed for lower prices, with subscribers regularly choosing plans that offered less than 10 Mbps, which is the FCC’s current required minimum for rural broadband subsidies. Because faster broadband typically costs more, higher minimum speeds are likely to blunt the (already likely low) beneficial effects of subsidies by increasing the price of eligible plans.Finally, subscribers generally expressed a preference to avoid digital literacy training classes. In one project, many participants were willing to forego an additional $10 per month savings or a free computer in order to avoid taking those classes. However, those results do not necessarily mean digital literacy training is not, or could not be, beneficial. The data from the pilot programs (weakly) show that those who took such classes were somewhat more likely to continue to subscribe once the subsidies expired. While that may reflect a self-selection effect, it nevertheless suggests that digital literacy training can plan a role. Still, the results also suggest that digital literacy training should be studied further to evaluate which aspects of it are most effective.

Overcoming barriers to cycling: understanding frequency of cycling in a University setting and the factors preventing commuters from cycling on a regular basis

Much local and regional transport policy is attempting to increase cycling as an everyday mode of travel through infrastructure changes, education initiatives, and safety campaigns. While considerable research has examined the influence of the built form on cycling, less research has examined the barriers that prevent people who wish to cycle more (as part of their routine) from doing so. This study examines several factors influencing the frequency by which people do (and do not) cycle in a campus setting in a large metropolitan area. Mixed methods reveal differences between barriers to cycling as well as the relative strength of these barriers across categories of age, sex, and current mode used. A multinomial logit model, which controls for residential self-selection effects, predicts whether and how often a respondent cycles based on socio-demographic and trip characteristics. The presence of cycle paths is found to be strongly associated with a higher frequency of cycling commutes. Additionally, an analysis of stated barriers reveals effort and a lack of safety as the most important barriers to potential cyclists. Finally, a qualitative analysis of respondents’ open-ended responses confirms the influence of bicycle paths, but reveals other factors such as the importance of improved interactions among various street users. Findings from this research can be of benefit to transportation engineers and planners who are aiming to increase the use of cycling among various groups of commuters.

Travel Plans for New Residential Developments: Measuring Self-Selection Effects to Better Understand Travel Behavior Impacts

Travel plans can be required for new residential developments as part of the land use planning and approvals process. The aim is to manage car use of residents by providing a package of tailored initiatives and facilities that support the use of more sustainable forms of transport. However, there is a limited understanding of the extent to which such packages have influenced travel behavior or simply attracted residents who were already making travel choices to reduce car use; the latter effect is commonly referred to as residential self-selection. In this study, a survey of residents in Melbourne, Victoria, Australia, was conducted at developments with and without travel plans. Propensity score matching (PSM)—based on a set of attitudinal, preference, and demographic variables—was then used to explore how residential self-selection could be analyzed in the context of travel plans. Results suggest that residents living in developments with travel plans have lower car ownership and higher levels of walking and cycling compared with residents living in developments without travel plans. PSM was deemed to be a suitable method for analyzing residential self-selection effects, yet a sufficient sample size is required to appropriately quantify these effects.

The Impact of Micro-Credit on Employment: Evidence from Bangladesh and Pakistan

This paper examines the impact of micro-credit on employment. Household-level data was collected, following a quasi-experimental design, in Bangladesh and Pakistan. Three borrower groups are compared: Current borrowers; Pipeline borrowers and Non-borrowers. Pipeline borrowers are included to control for self-selection effects. It is argued that micro-credit causes a substitution of employment away from employment-for-pay to self-employment. Therefore, the effect on total employment is ambiguous. OLS and fixed effects regression are used to examine separately self-employment and employment-for-pay between three groups of borrowers. For Pakistan, there is no evidence that micro-credit effects employment. However, for Bangladesh, there is robust evidence consistent with this hypothesis.

Self-Selection Effects in Service-Learning

This study directly examines the possibility of pre-existing differences between undergraduate students who choose to take service-learning classes compared to those who do not. Foremost among the findings, on most measures there was no significant effect of self-selection. However, students who chose a hypothetical course with a service-learning component reported higher civic responsibility and civic action scores, and reported lower socioeconomic status and greater enjoyment of past service learning than those who chose the hypothetical course without the service-learning component. Challenges and opportunities related to random assignment within service-learning research are discussed.

Neither bridging nor bonding: A test of socialization effects by ethnically diverse voluntary associations on participants' inter-ethnic tolerance, inter-ethnic trust and intra-ethnic belonging

The distinction between bridging and bonding associations is a cornerstone of social capital research. Nevertheless, this study is the first to provide a direct test of the socialization mechanism that supposedly causes ethnically mixed (bridging) associations to generate interethnic tolerance and trust, and homogenous (bonding) associations to cement self-affirming identities.This multilevel analysis of the Citizenship, Involvement & Democracy (CID) 1999/2000 survey data on Mannheim (Germany), Enschede (the Netherlands), and Aberdeen (Scotland) covers 3166 active participants in 645 associations. The CID includes objective, exogenous measures of each association's composition and aim. Socialization and self-selection effects are pulled apart through interactions with detailed measures of associational involvement.The results display no evidence for (diverse and homogenous) associations as socializing agents. Although inter-ethnic tolerance is higher in ethnically diverse associations, this should be attributed to self-selection effects.

Contact in context: does intergroup contact function (better) in high-threat contexts?

ABSTRACTAre interpersonal contacts effective in reducing group threat and prejudice in all contexts? Studies have found that the contact effect is stronger in regions and countries where large immigrant populations contribute to high levels of contextual group threat This paper tests the robustness of the observed positive association between contextual-level group threat and contact effects by identifying three methodological reasons for why the association might be spurious: (1) a potential omitted variable bias; (2) a potential self-selection effect; and (3) a potential ceiling effect. Using the 2002 European Social Survey, we find that the positive association is indeed robust. We interpret this as evidence that contact effects are strongest in those European contexts where the need for improved intergroup relations between immigrants and natives is most dire.

Trade union membership and paid vacation in Germany

AbstractIn Germany, dependent employees take almost 30 days of paid vacation annually. We enquire whether an individual’s trade union membership affects the duration of vacation. Using data from the German Socio-Economic Panel (SOEP) for the period 1985 to 2010 and employing pooled OLS-estimators, we find that being a union member goes along with almost one additional day of vacation per year. Estimations exploiting the panel structure of our data suggest that a smaller part of this vacation differential can be due to the union membership status, while self-selection effects play a more important role.

Mechanism of altruism approach to blood donor recruitment and retention: a review and future directions.

Why do people donate blood? Altruism is the common answer. However, altruism is a complex construct and to answer this question requires a systematic analysis of the insights from the biology, economics and psychology of altruism. I term this the mechanism of altruism (MOA) approach and apply it here for understanding blood donor motivation. The answer also has enormous implications for the type of interventions we choose to adopt as a society. A MOA approach so far shows that blood donors are a mixture of (i) warm-glow givers (donation is emotionally rewarding) and (ii) reluctant altruists (cooperate rather than defect when free-riding is high). Donors also show 'saintly sinning' with the extra 'moral currency' form blood donation allowing them to be less generous in other contexts. The MOA approach suggests why financial incentives, in terms of gifts/lottery tickets, are effective and suggests a number of novel interventions for donor recruitment: 'voluntary reciprocal altruism' and 'charitable incentivisation'. The MOA approach also highlights the need for an intervention developed specifically for recipients to allow them to show their gratitude to donors and for society to celebrate blood donation. It is suggests a 'Monument to Blood Donors' will achieve this. The approach suggests a number of novel research questions into (i) donor self-selection effects, (ii) conditional cooperation and (iii) construct overlap with Theory of Planned Behaviour (e.g. affective attitudes and warm-glow). The MOA offers a powerful way to understand blood donor motivations around altruism and develop theoretically driven interventions.

Commuting mode choice in transit oriented development: Disentangling the effects of competitive neighbourhoods, travel attitudes, and self-selection

This research identifies the commuting mode choice behaviour of 3537 adults living in different types of transit oriented development (TOD) in Brisbane by disentangling the effects of their “evil twin” transit adjacent developments (TADs), and by also controlling for residential self-selection, travel attitudes and preferences, and socio-demographic effects. A TwoStep cluster analysis was conducted to identify the natural groupings of respondents’ living environment based on six built environment indicators. The analysis resulted in five types of neighbourhoods: urban TODs, activity centre TODs, potential TODs, TADs, and traditional suburbs. HABITAT survey data were used to derive the commute mode choice behaviour of people living in these neighbourhoods. In addition, statements reflecting both respondents’ travel attitudes and living preferences were also collected as part of the survey. Factor analyses were conducted based on these statements and these derived factors were then used to control for residential self-selection. Four binary logistic regression models were estimated, one for each of the travel modes used (e.g. public transport, active transport, less sustainable transport such as the car/taxi, and other), to differentiate between the commuting behaviour of people living in the five types of neighbourhoods. The findings verify that urban TODs enhance the use of public transport and reduce car usage. No significant difference was found in the commuting behaviour between respondents living in traditional suburbs and TADs. The results confirm the hypothesis that TADs are the “evil twin” of TODs. The data indicates that TADs and the mode choices of residents in these neighbourhoods is a missed transport policy opportunity. Further policy efforts are required for a successive transition of TADs into TODs in order to realise the full benefits of these. TOD policy should also be integrated with context specific TOD design principles.

Restaurant tipping in a field experiment: How do customers tip when they receive too much change?

Tipping behavior is analyzed in a field experiment where restaurant customers received excessive change, either 10 or 40 Shekels (about $3 versus $12). One third of the tables reported the extra change to the server and returned it. Tips were higher with the higher level of extra change. Returning the extra change was negatively correlated with tips. The interaction between the level of extra change and whether it was returned had no effect. Possible explanations that tips are higher when the excessive change is not returned due to a positive income effect or perceiving paying a tip out of excessive change as less costly because it is a forgone gain and not a loss, are not supported by the data. Subjects may have exhibited moral licensing and moral cleansing effects. These effects, however, were possibly mitigated by a self-selection effect going in the opposite direction: those who are more generous or altruistic by their nature are more likely to return the extra change and also more likely to tip generously. Receiving the larger amount of extra change may result in feelings of good mood, perceived luckiness, or individuation and unconscious fear of being observed, which increase tips. Interestingly, these feelings seem to remain even if the extra change was returned.

An Empirical Investigation of Self-Selection Bias and Factors Influencing Review Helpfulness

This paper build on 1 489194 product reviews from 30 product categories retrieved from Amazon.com. Product categories are classified by use of natural language analysis tools with computing of subjectivity scores reflecting a search/experience product dimension. Results show a distinct effect of self-selection where the average review score gradually decreases. For most products, no undershooting period was observed, even though a limited number of products groups had this development pattern. Review length, verified purchase and use of real names contributed to increasing helpfulness ratings. The results further suggest search products to be more influenced by review length than experience products.

Has Mexico City’s shift to commercially produced housing increased car ownership and car use?

Mexico City’s principal form of housing production has shifted over the past two decades. More households now purchase houses in large commercially built housing developments than move into informal settlements. Looking at 1500 households in two suburban municipalities from a 2007 metropolitan travel survey, this study is the first to quantify differences in car ownership and car use across households in informal settlements and commercial housing developments. Accounting for income, proxies for wealth, household composition, and geography, households living in commercial housing developments are likely to own more cars and drive more than similar households in neighboring informal settlements. A test for residential self-selection finds no unobserved correlations across households that own cars and live in commercial housing developments, suggesting that the included controls do a good job of capturing the effects of residential self-selection or that the effects are limited. Something about the local land use and design of new commercial housing developments appears conducive to car ownership and use. Differences between the two settlement types, including more parking, wider streets, less-connected street-grids, and less accessible transit stops in commercial settlements, likely play a role.

Costs of Trade and Self-selection into Exporting and Importing: The Case of Turkish Manufacturing Firms

Abstract This paper focuses on self-selection into trade by exporting and importing firms, and on the presence of differential variable and sunk costs between exporters and importers across different categories of imports. The authors use a rich and recent dataset for Turkish manufacturing firms for the period 2003–2010. This allows them to provide a comprehensive analysis of firm heterogeneity and the connection between firm-level performance and international trade. They provide evidence on the remarkable heterogeneity across firms where only-importers (importers) perform better than only-exporters (exporters). The authors detect a self-selection effect for both importing and exporting firms with a stronger effect for importers. The results suggest that the nature of sunk costs varies between importing and exporting activities with importers facing higher sunk costs. Tariffs represent a potentially important source of variation in the variable costs of trading. When taking the tariffs faced by firms into account, the authors find that the self-selection effect associated with sunk costs is still present but greatly reduced with a smaller reduction for importers compared to exporters.

Schools or Pools of Democracy? A Longitudinal Test of the Relation Between Civic Participation and Political Socialization

In this contribution we demonstrate how the usage of panel data offers possibilities for testing new hypotheses in a research tradition with a long history in political science. Focusing on citizens’ transitions in and out of voluntary associations, we tested four possible explanations for the well-documented correlation between civic engagement and political socialization. Two are due to self-selection effects (pools of democracy), and two are due to socialization effects (schools of democracy). Our analyses offer little support for the idea of voluntary associations playing a major role in political socialization processes: our latent growth curve models showed no or very little increase of political discussion, interest, efficacy, and action among those who became actively involved in voluntary associations. In contrast, we found convincing evidence for our pools-of-democracy hypotheses, and the self-selection turns out to be a double-edged sword: politically engaged citizens are more likely to join voluntary associations and less likely to leave them. These findings challenge the conclusions of many studies based on cross-sectional data.

An agent-based evaluation of impacts of transport developments on the modal shift in Tehran, Iran

Changes in travel modes used by people, particularly reduction of the private car use, is an important determinant of effectiveness of transportation plans. Because of dependencies between the choices of residential location and travel mode, integrated modelling of these choices has been proposed by some researchers. In this paper, an agent-based microsimulation model has been developed to evaluate impacts of different transport development plans on choices of residential location and commuting mode of tenant households in Tehran, the capital of Iran. In the proposed model, households are considered as agents who select their desired residential location using a constrained NSGA-II algorithm and in a competition with other households. In addition, they choose their commuting mode by applying a multicriteria decision-making method. Afterwards, effects of development of a new highway, subway and bus rapid transit (BRT) line on their residential location and commuting mode choices are evaluated. Results show that despite the residential self-selection effects, these plans result in considerable changes in the commuting mode of different socio-economic categories of households. Development of the new subway line shows promising results by reducing the private car use among the all socio-economic categories of households. But the new highway development unsatisfactorily results in increase in the private car use. In addition, development of the new BRT line does not show significant effects on the commuting mode change, particularly on decrease in the private car use.