Institutions are an important means for fostering prosocial behaviors, but in many contexts their scope is limited and they govern only a subset of all socially desirable acts. We study experimentally how the presence and nature of an institution that enforces prosocial behavior in one domain affects behavior in a similar but unregulated domain. Groups play two identical public good games, with cooperation institutionally enforced in one game. The presence of an institution in one game generally enhances cooperation in the other game, thus documenting a positive spillover effect. These indirect spillover effects are economically substantial, amounting up to 30 to 40 percent of the direct effect of institutions. In addition, we find evidence for sequential spillover effects, meaning that behavior is affected by the institution even after it is removed. We also observe that institutions enhance prosocial preferences and beliefs about others’ prosocial behavior, even toward strangers, suggesting that both factors are drivers of the observed spillover effects. We further explore other aspects influencing spillover effects, including characteristics of an institution, such as whether it is exogenously imposed or endogenously determined.
We provide a direct test of the impact of altruism on remittances. From a sample of Indian migrant workers in Qatar, we elicit the propensity to share with others from their responses in a dictator game and use it as a proxy for altruism. For the entire sample, we find that altruism does not seem to matter. However, we document a strong positive relationship between altruism and remittances for a subset of migrants with a loan obligation, whereas indirect tests of altruism, typically used in the literature, would fail to establish this relationship. We explain the role of loan obligations with a standard remittance model extended with reference-dependent preferences.
Efficiently growing a group often requires integrating individuals from lower performing entities. We explore the effectiveness of policies intended to facilitate such integration, using an experiment that models production as a coordination game. We create an efficient group and an inefficient one. We then allow individuals to move into the efficient group under different mechanisms. We investigate the use of an entry quota, an entry quiz and combinations of the two in order to try to understand if and why the institutions are effective. We find that both restrictions work to maintain efficient coordination but they are effective for different reasons.
In Europe, more than 250,0 0 0 university students spend one or two semesters abroad every year. This study explores whether a short time abroad contributes to the acquisition of foreign language proficiency. We use a newly available dataset about almost the totality of Italian graduates and two alternative in- struments to address the endogeneity of studying abroad. Both instruments display similar results. The effect of studying abroad on foreign language proficiency is remarkable, although extremely heteroge- neous across languages. Languages more rewarded by the labor market are those that are harder to learn in a short time abroad.
The delivery of basic health products and services remains abysmal in many parts of the world where child mortality is high. This paper shows the results from a largescale randomized evaluation of a novel “social entrepreneurship” approach to health care delivery. In randomly selected villages a sales agent was locally recruited and incentivized to conduct home visits, educate households on essential health behaviors, provide medical advice and referrals, and sell preventive and curative health products. Results after three years show substantial health impact: under-5 child mortality was reduced by 27% at an estimated cost of $71 per life-year saved.
We study competitive equilibrium in a signaling economy with heterogeneously informed buyers. In terms of the classic Spence (1973) model of job market signaling, firms have access to direct but imperfect information about worker types, in addition to observing their education. Firms can be ranked according to the quality of their information, i.e. their expertise. In equilibrium, some high type workers forgo signaling and are hired by better informed firms, who make positive profits. Workers’ education decisions and firms’ use of their expertise are strategic complements, allowing for multiple equilibria. We characterize wage dispersion and the extent of signaling as a function of the distribution of expertise among firms. The market can create insufficient or excessive incentives for firms to acquire information, and we provide a formula to measure this inefficiency. Our model can also be applied to a variety of other signaling problems, including securitization, corporate financial structure, insurance markets, or dividend policy.
According to theoretical accounts, both, N-back and complex span tasks mainly require working memory (WM) processing. In contrast, simple span tasks conceptually mainly require WM storage. Thus, conceptually, an N-back task and a complex span task share more commonalities as compared to a simple span task. In the current study, we compared an N-back task, a complex operation span task (Ospan), and a simple digit span task (Dspan) by means of typical WM load-related measures of the Electroencephalogram (EEG) like the parietal alpha and beta frequency band power, the frontal theta frequency band power, and the P300 amplitude, to examine whether these tasks would show commonalities or differences in WM processing-load. We expected that increasing WM-load would generally lead to a decreased alpha and beta frequency band power, an increased theta frequency band power, and a decreased P300 amplitude. Yet, based on the conceptual considerations, we hypothesized that the outcomes of these measures would be more comparable between the N-back and the Ospan as compared to the Dspan. Our hypotheses were partly confirmed. The N-back and the Ospan showed timely more prolonged alpha frequency band power effects as compared to the Dspan. This might indicate higher demands on WM processing in the former two tasks. The theta frequency band power and the P300 amplitude were most pronounced in the N-back task as compared to both span tasks. This might indicate specific demands on cognitive control in the N-back task. Additionally, we observed that behavioral performance measures correlated with changes in EEG alpha power of the N-back and the Ospan, yet not of the Dspan. Taken together, the hypothesized conceptual commonalities between the N-back task and the Ospan (and, for the Dspan, differences) were only partly confirmed by the electrophysiological WM load-related measures, indicating a potential need for reconsidering the theoretical accounts on WM tasks and the value of a closer link to electrophysiological research herein.
The transmit–receive (Tx/Rx) birdcage head coil is often used for excitation instead of the body coil because of the presumably lower risk of heating in and around conductive implants. However, this common practice has not been systematically tested. To investigate whether the Tx/Rx birdcage head coil produces less heating than the body coil when scanning individuals with implants, we used a 3T clinical scanner and made temperature measurements around a straight 15 cm conductor using either the Tx/Rx body or the head coil for excitation. Additionally, the transmitted fields of a Tx/Rx head coil were measured both in air and in gel using a resonant and a non-resonant B field probes as well as a non-resonant E field probe. Simulations using a finite-difference time domain solver were compared with the experimental findings. When the body coil was used for excitation, we observed heating around the 15 cm wire at various anatomical locations (both within and outside of the active volume of the head coil). Outside its active area, no such heating was observed while using the Tx/Rx head coil for excitation. The E and B fields of the Tx/Rx birdcage head coil extended well-beyond the physical dimensions of the coil. In air, the fields were monotonically decreasing, while in gel they were more complex with local maxima at the end of the ASTM phantom. These experimental findings were line with the simulations. While caution must always be exercised when scanning individuals with metallic implants, these findings support the use of the Tx/Rx birdcage head coil in place of the body coil at 3T in order to reduce the risk of heating in and around conductive implants that are remote from the head coil.
It is well established that the frontal eye-fields (FEF) in the dorsal attention network (DAN) guide top-down selective attention. In addition, converging evidence implies a causal role for the FEF in attention shifting, which is also known to recruit the ventral attention network (VAN) and fronto-striatal regions. To investigate the causal influence of the FEF as (part of) a central hub between these networks, we applied thetaburst transcranial magnetic stimulation (TBS) off-line, combined with functional magnetic resonance (fMRI) during a cued visuo-spatial attention shifting paradigm.
We found that TBS over the right FEF impaired performance on a visual discrimination task in both hemifields following attention shifts, while only left hemifield performance was affected when participants were cued to maintain the focus of attention. These effects recovered ca. 20 min post stimulation. Furthermore, particularly following attention shifts, TBS suppressed the neural signal in bilateral FEF, right inferior and superior parietal lobule (IPL/SPL) and bilateral supramarginal gyri (SMG). Immediately post stimulation, functional connectivity was impaired between right FEF and right SMG as well as right putamen. Importantly, the extent of decreased connectivity between right FEF and right SMG correlated with behavioural impairment following attention shifts.
The main finding of this study demonstrates that influences from right FEF on SMG in the ventral attention network causally underly attention shifts, presumably by enabling disengagement from the current focus of attention.
