Eine experimentalökonomische Untersuchung von Recyclingverhalten

Natürliche Ressourcen stellen einen bedeutenden Inputfaktor in Produktionsprozessen dar und tragen zum menschlichen Wohlstand bei. Sie sind jedoch nur begrenzt verfügbar. Dies gefährdet zukünftiges Wachstum und birgt Konfliktpotential. Zudem werden natürliche Ressourcen durch negative Umweltauswirkungen entlang der Wertschöpfungskette beeinträchtigt und dienen etwa als Senke für klimaschädliche Treibhausgasemissionen oder Abfälle. Somit zieht die Ressourcenknappheit vielfältige lokale wie globale Probleme nach sich, denen im Hinblick auf Nachhaltigkeitsziele durch den Aufbau einer Kreislaufwirtschaft entgegengewirkt werden kann. Die Transformation der Wirtschaft erfordert neben der Schaffung geeigneter politischer Rahmenbedingungen und erheblicher technologischer Investitionen insbesondere auch die Mitwirkung von Privathaushalten, damit Abfälle recycelt und die darin enthaltenen Rohstoffe im Kreislauf gehalten werden können. Aus ökonomischer Perspektive besteht diesbezüglich ein Dilemma, da private Kosten des Recyclings den unmittelbar daraus resultierenden privaten Nutzen übersteigen: Während rational nutzenmaximierende Akteure entsprechend der Standardtheorie auf jegliche Recyclingaktivität verzichten, könnten sie bei Kooperation wechselseitig vom nicht-ausschließbaren Nutzen des Recyclings profitieren und sich insgesamt besserstellen. Die Ökonomik bietet zwar mit Instrumenten wie dem Pfandsystem Lösungen an – diese unterliegen jedoch Grenzen und lassen sich praktisch nicht zur Regulierung aller relevanten Bereiche einsetzen. In dieser Arbeit wird die freiwillige Mitwirkung am Recycling in unterschiedlichen institutionellen Settings experimentalökonomisch im Labor untersucht. Grundlage bildet ein erweitertes Öffentliches-Gut-Spiel, in dem Recycling als Investition in ein Öffentliches Gut Umwelt- und Ressourcenschutz interpretiert wird. Konkret wird die Gesellschaft in zwei gleichgroße Klubs unterteilt. Die Gesellschaftsmitglieder erhalten dann die Möglichkeit zur Investition in ein gesamtgesellschaftlich nutzenstiftendes Öffentliches Gut sowie in ihr Klubgut: Der hier erzielte Nutzen kommt exklusiv den Klubmitgliedern zugute. Vor diesem Hintergrund bezieht sich die Fragestellung dieser Arbeit auf die Bedeutung der Einführung exklusiver Recyclingsysteme, ihre Zusammensetzung sowie die Wirkung eines Wettbewerbs zwischen ihnen. Die Ergebnisse zeigen, dass die Neueinführung der Klubgüter im Laufe des Experiments zu höheren Beiträgen in die Klubgüter und schließlich zu höheren Gesamtbeiträgen führt. Hinsichtlich der Klubeinteilung wird zwischen zufälliger Einteilung und der Einteilung in Klubs mit hoher, respektive niedriger Umwelteinstellung unterschieden. Die einstellungsbezogene Klubeinteilung führt zu höheren Beiträgen zum Öffentlichen Gut sowie zu höheren Gesamtbeiträgen. Auf Klubebene leisten die Mitglieder der Klubs mit höherer Umwelteinstellung höhere Gesamtbeiträge. Die wettbewerbliche Komponente besteht darin, dass in jeder Gesellschaft der Klub, in den innerhalb eines bestimmten Zeitraums weniger investiert wurde, vorzeitig aufgelöst wird. Die betroffenen Mitglieder können fortan nur noch in das Öffentliche Gut investieren. Bei zufälliger Klubeinteilung lässt sich diesbezüglich kein signifikanter Unterschied feststellen. Allerdings wirkt sich der Wettbewerb in Kombination mit einstellungsbezogener Gruppeneinteilung tendenziell kontraproduktiv auf die Gesamtbeiträge aus. Dies ist zuvorderst darauf zurückzuführen, dass die Mitglieder der Klubs mit niedriger Umwelteinstellung signifikant weniger zum Klubgut beitragen als ohne Wettbewerb. Zusammengenommen lassen die Ergebnisse darauf schließen, dass die Einführung zusätzlicher Recyclingoptionen mit spürbarem Nutzen sowie die Verschiebung von Recyclingentscheidungen in den Kontext sozial verbundener Gruppen mit nicht-diskriminierender Identität zu höherer Beteiligung am Recycling führen.Natural resources play a crucial role in production processes and contribute to human prosperity However, these resources are limited. This poses a threat to the future growth and may cause conflicts in the long run. Additionally, the usage of natural resources has a negative impact on the environment at almost every step along the value chain. For instance, natural resources act as sinks for greenhouse gas emissions or waste. Summed up, resource scarcity leads to various local and global issues that can be resolved by developing a circular economy. Apart from creating adequate policy frameworks and making substantial technological investments, it is crucial to have households involved in the economic transformation: By recycling their waste, they retain the raw materials in the cycle. In economic terms, this poses a dilemma, as the costs of recycling incurred by private households exceed the direct benefits derived from it. Although standard economic theory suggests that rational and utility-maximizing agents should refrain from recycling, they could benefit from the non-excludable advantages of recycling and improve their overall outcome if they cooperate. While the economic instruments such as deposit systems could offer potential solutions, its versatility is limited and cannot be applied to regulate all relevant areas in practice. This work investigates the voluntary participation in recycling in different institutional settings by using experimental methods in the laboratory. The research is based on an extended Public Goods Game where recycling is interpreted as an investment in the environment and resource protection. Specifically, the population is divided into two equal-sized clubs. All members of the population are then given the opportunity to invest in either a Public Good that benefits the society as a whole, or in their own club where the achieved benefit is exclusively for club members. Against this background, this work's focus is on the significance of exclusive recycling systems, their composition, and the effects of competition between them. The results indicate that the introduction of club goods during the experiment leads to higher contributions towards them and results in higher total contributions. Regarding club division, a distinction is made between random division and division into clubs with their members having high versus low environmental attitudes. The club division based on attitude leads to higher contributions to the Public Good as well as higher total contributions. At the club level, members of clubs with relatively high environmental attitudes show higher total contributions. The competitive component is that within each society, the club where less has been invested within a certain period gets dissolved earlier. From that point on, the involved members are only permitted to invest in the Public Good. Random club assignments did not result in any substantial contrast. Nevertheless, scheduling competitions along with attitudinal grouping leads to an negative influence on the overall contributions. This mainly results from the reduced contribution of members from clubs with low environmental attitudes to the club's benefit as compared to those without competition. Collectively, the findings imply that the introduction of more recycling options with tangible benefits leads to higher recycling participation – as well as shifting recycling decisions to socially connected groups with non-discriminatory identities

Recycling behavior of private households: an empirical investigation of individual preferences in a club good experiment

While recycling helps to limit the use of primary resources, it also requires considerable technological investments in regional circular flow systems. The effectiveness of recycling systems, however, also depends on household behavior. Therefore, current research increasingly focuses on behavioral and psychological theories of altruism, moral behavior, and social preferences. From an economic perspective, recycling systems can be understood as public goods with contributions resulting in positive externalities. In this context, the literature shows that recycling behavior highly depends on the perception of how others behave. In neutrally framed public good experiments, contributions tend to increase when alternative public goods are offered and group identity is generated. We aim to contribute to this discussion by observing household behavior concerning recycling opportunities in controlled settings. For this purpose, we study a laboratory experiment in which individuals con‑tribute to recycling systems: At first, only one public recycling system (public good) is offered. After dividing societies into two clubs, “high” and “low” according to their environmental attitudes, excludable club systems (club goods) are added as alternative recycling options for each club. The results of our pilot experiment show that adding a more exclusive recycling club option increases individual contributions to recycling compared with a pure public good framework. However, this increase in cooperation is only significant for those clubs where members with higher environmental attitudes are pooled

A communal catalogue reveals Earth's multiscale microbial diversity

Our growing awareness of the microbial world's importance and diversity contrasts starkly with our limited understanding of its fundamental structure. Despite recent advances in DNA sequencing, a lack of standardized protocols and common analytical frameworks impedes comparisons among studies, hindering the development of global inferences about microbial life on Earth. Here we present a meta-analysis of microbial community samples collected by hundreds of researchers for the Earth Microbiome Project. Coordinated protocols and new analytical methods, particularly the use of exact sequences instead of clustered operational taxonomic units, enable bacterial and archaeal ribosomal RNA gene sequences to be followed across multiple studies and allow us to explore patterns of diversity at an unprecedented scale. The result is both a reference database giving global context to DNA sequence data and a framework for incorporating data from future studies, fostering increasingly complete characterization of Earth's microbial diversity.Peer reviewe

A communal catalogue reveals Earth’s multiscale microbial diversity

Our growing awareness of the microbial world’s importance and diversity contrasts starkly with our limited understanding of its fundamental structure. Despite recent advances in DNA sequencing, a lack of standardized protocols and common analytical frameworks impedes comparisons among studies, hindering the development of global inferences about microbial life on Earth. Here we present a meta-analysis of microbial community samples collected by hundreds of researchers for the Earth Microbiome Project. Coordinated protocols and new analytical methods, particularly the use of exact sequences instead of clustered operational taxonomic units, enable bacterial and archaeal ribosomal RNA gene sequences to be followed across multiple studies and allow us to explore patterns of diversity at an unprecedented scale. The result is both a reference database giving global context to DNA sequence data and a framework for incorporating data from future studies, fostering increasingly complete characterization of Earth’s microbial diversity

Brain Aging and APOE ε4 Interact to Reveal Potential Neuronal Compensation in Healthy Older Adults

Compensation implies the recruitment of additional neuronal resources to prevent the detrimental effect of age-related neuronal decline on cognition. Recently suggested statistical models comprise behavioral performance, brain activation, and measures related to aging- or disease-specific pathological burden to characterize compensation. Higher chronological age as well as the APOE ε4 allele are risk factors for Alzheimer's disease. A more biological approach to characterize aging compared with chronological age is the brain age gap estimation (BrainAGE), taking into account structural brain characteristics. We utilized this estimate in an fMRI experiment together with APOE variant as measures related to pathological burden and aimed at identifying compensatory regions during working memory (WM) processing in a group of 34 healthy older adults. According to published compensation criteria, better performance along with increased brain activation would indicate successful compensation. We examined the moderating effects of BrainAGE on the relationship between task performance and brain activation in prefrontal cortex, as previous studies suggest predominantly frontal compensatory activation. Then we statistically compared them to the effects of chronological age (CA) tested in a previous study. Moreover, we examined the effects of adding APOE variant as a further moderator. Herewith, we strived to uncover neuronal compensation in healthy older adults at risk for neurodegenerative disease. Higher BrainAGE alone was not associated with an increased recruitment in prefrontal cortex. When adding APOE variant as a second moderator, we found an interaction of BrainAGE and APOE variant, such that ε4 carriers recruited right inferior frontal gyrus with higher BrainAGE to maintain WM performance, thus showing a pattern compatible with successful neuronal compensation. Exploratory analyses yielded similar patterns in left inferior and bilateral middle frontal gyrus. These results contrast those from a previous study, where we found no indication of compensation in prefrontal cortex in ε4 carriers with increasing CA. We conclude that BrainAGE together with APOE variant can help to reveal potential neuronal compensation in healthy older adults. Previous results on neuronal compensation in frontal areas corroborate our findings. Compensatory brain regions could be targeted in affected individuals by training or stimulation protocols to maintain cognitive functioning as long as possible

Brain Aging and APOE ε4 Interact to Reveal Potential Neuronal Compensation in Healthy Older Adults

Compensation implies the recruitment of additional neuronal resources to prevent the detrimental effect of age-related neuronal decline on cognition. Recently suggested statistical models comprise behavioral performance, brain activation, and measures related to aging- or disease-specific pathological burden to characterize compensation. Higher chronological age as well as the APOE ε4 allele are risk factors for Alzheimer's disease. A more biological approach to characterize aging compared with chronological age is the brain age gap estimation (BrainAGE), taking into account structural brain characteristics. We utilized this estimate in an fMRI experiment together with APOE variant as measures related to pathological burden and aimed at identifying compensatory regions during working memory (WM) processing in a group of 34 healthy older adults. According to published compensation criteria, better performance along with increased brain activation would indicate successful compensation. We examined the moderating effects of BrainAGE on the relationship between task performance and brain activation in prefrontal cortex, as previous studies suggest predominantly frontal compensatory activation. Then we statistically compared them to the effects of chronological age (CA) tested in a previous study. Moreover, we examined the effects of adding APOE variant as a further moderator. Herewith, we strived to uncover neuronal compensation in healthy older adults at risk for neurodegenerative disease. Higher BrainAGE alone was not associated with an increased recruitment in prefrontal cortex. When adding APOE variant as a second moderator, we found an interaction of BrainAGE and APOE variant, such that ε4 carriers recruited right inferior frontal gyrus with higher BrainAGE to maintain WM performance, thus showing a pattern compatible with successful neuronal compensation. Exploratory analyses yielded similar patterns in left inferior and bilateral middle frontal gyrus. These results contrast those from a previous study, where we found no indication of compensation in prefrontal cortex in ε4 carriers with increasing CA. We conclude that BrainAGE together with APOE variant can help to reveal potential neuronal compensation in healthy older adults. Previous results on neuronal compensation in frontal areas corroborate our findings. Compensatory brain regions could be targeted in affected individuals by training or stimulation protocols to maintain cognitive functioning as long as possible

Table1.DOCX

<p>Compensation implies the recruitment of additional neuronal resources to prevent the detrimental effect of age-related neuronal decline on cognition. Recently suggested statistical models comprise behavioral performance, brain activation, and measures related to aging- or disease-specific pathological burden to characterize compensation. Higher chronological age as well as the APOE ε4 allele are risk factors for Alzheimer's disease. A more biological approach to characterize aging compared with chronological age is the brain age gap estimation (BrainAGE), taking into account structural brain characteristics. We utilized this estimate in an fMRI experiment together with APOE variant as measures related to pathological burden and aimed at identifying compensatory regions during working memory (WM) processing in a group of 34 healthy older adults. According to published compensation criteria, better performance along with increased brain activation would indicate successful compensation. We examined the moderating effects of BrainAGE on the relationship between task performance and brain activation in prefrontal cortex, as previous studies suggest predominantly frontal compensatory activation. Then we statistically compared them to the effects of chronological age (CA) tested in a previous study. Moreover, we examined the effects of adding APOE variant as a further moderator. Herewith, we strived to uncover neuronal compensation in healthy older adults at risk for neurodegenerative disease. Higher BrainAGE alone was not associated with an increased recruitment in prefrontal cortex. When adding APOE variant as a second moderator, we found an interaction of BrainAGE and APOE variant, such that ε4 carriers recruited right inferior frontal gyrus with higher BrainAGE to maintain WM performance, thus showing a pattern compatible with successful neuronal compensation. Exploratory analyses yielded similar patterns in left inferior and bilateral middle frontal gyrus. These results contrast those from a previous study, where we found no indication of compensation in prefrontal cortex in ε4 carriers with increasing CA. We conclude that BrainAGE together with APOE variant can help to reveal potential neuronal compensation in healthy older adults. Previous results on neuronal compensation in frontal areas corroborate our findings. Compensatory brain regions could be targeted in affected individuals by training or stimulation protocols to maintain cognitive functioning as long as possible.</p

Table2.DOCX

<p>Compensation implies the recruitment of additional neuronal resources to prevent the detrimental effect of age-related neuronal decline on cognition. Recently suggested statistical models comprise behavioral performance, brain activation, and measures related to aging- or disease-specific pathological burden to characterize compensation. Higher chronological age as well as the APOE ε4 allele are risk factors for Alzheimer's disease. A more biological approach to characterize aging compared with chronological age is the brain age gap estimation (BrainAGE), taking into account structural brain characteristics. We utilized this estimate in an fMRI experiment together with APOE variant as measures related to pathological burden and aimed at identifying compensatory regions during working memory (WM) processing in a group of 34 healthy older adults. According to published compensation criteria, better performance along with increased brain activation would indicate successful compensation. We examined the moderating effects of BrainAGE on the relationship between task performance and brain activation in prefrontal cortex, as previous studies suggest predominantly frontal compensatory activation. Then we statistically compared them to the effects of chronological age (CA) tested in a previous study. Moreover, we examined the effects of adding APOE variant as a further moderator. Herewith, we strived to uncover neuronal compensation in healthy older adults at risk for neurodegenerative disease. Higher BrainAGE alone was not associated with an increased recruitment in prefrontal cortex. When adding APOE variant as a second moderator, we found an interaction of BrainAGE and APOE variant, such that ε4 carriers recruited right inferior frontal gyrus with higher BrainAGE to maintain WM performance, thus showing a pattern compatible with successful neuronal compensation. Exploratory analyses yielded similar patterns in left inferior and bilateral middle frontal gyrus. These results contrast those from a previous study, where we found no indication of compensation in prefrontal cortex in ε4 carriers with increasing CA. We conclude that BrainAGE together with APOE variant can help to reveal potential neuronal compensation in healthy older adults. Previous results on neuronal compensation in frontal areas corroborate our findings. Compensatory brain regions could be targeted in affected individuals by training or stimulation protocols to maintain cognitive functioning as long as possible.</p