Of the Stability of Partnerships When Individuals Have Outside Options, or Why Allowing Exit is Inefficient

Should people be allowed to leave joint projects freely or should they be deterred from breaking off? This depends on why people stop collaborating and whether they have good reasons to do so. We explore the factors that lead to the breakdown of partnerships by studying a public good game with imperfect public monitoring and an exit option. In our experiment, subjects were assigned a partner with whom they could contribute over several periods to a public good with stochastic out- comes. They could choose in each period between participating in the public project or working on their own. We find there was excessive exit especially because subjects over-estimated the likelihood their partner would leave. Treatments with high barriers to exit generated higher welfare overall as they fostered stability and prevented inefficient breakdowns in relationships. There were differences across treatments in the intensity with which different factors drove the choice to work alone. Differences in expected payoffs between independent and group work were more important as a driver of exit in treatments with low barriers to exit. The intensity of other factors was more constant across treatments, including whether the common project failed in the previous period, the belief that one´s partner did not want to maintain the partnership and the belief that he exerted less effort than oneself

Lipid and protein content profiling of isolated native autophagic vesicles

Autophagy is responsible for clearance of an extensive portfolio of cargoes, which are sequestered into vesicles, called autophagosomes, and are delivered to lysosomes for degradation. The pathway is highly dynamic and responsive to several stress conditions. However, the phospholipid composition and protein contents of human autophagosomes under changing autophagy rates are elusive so far. Here, we introduce an antibody-based FACS-mediated approach for the isolation of native autophagic vesicles and ensured the quality of the preparations. Employing quantitative lipidomics, we analyze phospholipids present within human autophagic vesicles purified upon basal autophagy, starvation, and proteasome inhibition. Importantly, besides phosphoglycerides, we identify sphingomyelin within autophagic vesicles and show that the phospholipid composition is unaffected by the different conditions. Employing quantitative proteomics, we obtain cargo profiles of autophagic vesicles isolated upon the different treatment paradigms. Interestingly, starvation shows only subtle effects, while proteasome inhibition results in the enhanced presence of ubiquitin-proteasome pathway factors within autophagic vesicles. Thus, here we present a powerful method for the isolation of native autophagic vesicles, which enabled profound phospholipid and cargo analyses

Arf1/COPI machinery acts directly on lipid droplets and enables their connection to the ER for protein targeting.

Lipid droplets (LDs) are ubiquitous organelles that store neutral lipids, such as triacylglycerol (TG), as reservoirs of metabolic energy and membrane precursors. The Arf1/COPI protein machinery, known for its role in vesicle trafficking, regulates LD morphology, targeting of specific proteins to LDs and lipolysis through unclear mechanisms. Recent evidence shows that Arf1/COPI can bud nano-LDs (∼60 nm diameter) from phospholipid-covered oil/water interfaces in vitro. We show that Arf1/COPI proteins localize to cellular LDs, are sufficient to bud nano-LDs from cellular LDs, and are required for targeting specific TG-synthesis enzymes to LD surfaces. Cells lacking Arf1/COPI function have increased amounts of phospholipids on LDs, resulting in decreased LD surface tension and impairment to form bridges to the ER. Our findings uncover a function for Arf1/COPI proteins at LDs and suggest a model in which Arf1/COPI machinery acts to control ER-LD connections for localization of key enzymes of TG storage and catabolism. DOI: http://dx.doi.org/10.7554/eLife.01607.001

Unprecedented staining of polar lipids by a luminescent rhenium complex revealed by FTIR microspectroscopy in adipocytes.

Fourier transform infrared (FTIR) microspectroscopy and confocal imaging have been used to demonstrate that the neutral rhenium(i) tricarbonyl 1,10-phenanthroline complex bound to 4-cyanophenyltetrazolate as the ancillary ligand is able to localise in regions with high concentrations of polar lipids such as phosphatidylethanolamine (PE), sphingomyelin, sphingosphine and lysophosphatidic acid (LPA) in mammalian adipocytes

Crime, Inequality, and the Private Provision of Security

In a high-crime environment with many high-income citizens, private security companies which offer protection against crime can flourish. In this article crime is modelled as a game where richer victims yield a higher return on crime, but with decreasing returns to crime as more criminals choose crime to supplement their income. Private security providers offer protection against crime and face Cournot competition. The model allows for the analysis of market clearing prices for effort against crime. Among the implications of the model are that rising inequality will lead to more expenditure on protection against crime, and that the upper income classes are suffering from the same or lower crime density than the middle income class. Taking into account the response of criminals and victims, rising inequality can actually lead to less crime if either (i) the legal income opportunity of the marginal criminal increases or (ii) marginal utility from income decreases and richer individuals spend a higher proportion of their income on protection (i.e. protection is a superior good). Often the middle class suffers from higher crime densities as inequality increases, as the increased spending on protection by the upper class (i) shifts crime to the middle class and (ii) increases market prices for protection, leaving the middle class with less affordable protection against crime. Emigration of the middle class can then further increase inequality. This highlights the importance of taking into account the response of individuals against crime and shows that the link between inequality and crime is a complex one.In diesem Artikel wird Kriminalität als Spiel modelliert, in welchem wohlhabenere Opfer mehr Gewinn erbringen; dieser Gewinn nimmt aber ab, je mehr Kriminelle sich auf wohlhabene Opfer konzentrieren. Private Sicherheitsdienstleister bieten Schutz gegen Kriminalität an und stehen im Cournot-Wettbewerb miteinander. Das Modell erlaubt die Untersuchung markträumender Preise für Sicherheitsdienstleistungen. Das Modell impliziert unter anderem, dass steigende Ungleichheit der Einkommensverteilung zu höheren Ausgaben für Sicherheitsdienstleistungen führt, und dass die oberen Einkommensschichten unter dem gleichen oder sogar geringeren Maß an Kriminalität leiden als mittlere Einkommensschichten. Es zeigt sich, dass steigende Ungleichheit Kriminalität sogar reduzieren kann, wenn (i) legale Einkommensmöglichkeiten des marginalen Kriminellen steigen und/oder (ii) der Grenznutzen des Einkommens abnimmt und wohlhabendere Individuen einen höheren Anteil ihres Einkommens für (superiore) Sicherheitsdienstleistungen ausgeben. Mittlere Einkommensschichten können bei steigender Ungleichheit unter mehr Kriminalität leiden, da steigende Ausgaben für Sicherheit durch höhere Einkommensschichten (i) Kriminalität auf niedrigere Einkommensschichten verlagern und (ii) den Marktpreis für Sicherheitsdienstleistungen erhöhen. Emigration der mittleren Einkommensschichten kann dann zu einem weiteren Anstieg der Ungleichheit führen