INSTITUTIONS AND THE VICIOUS CIRCLE OF DISTRUST IN THE RUSSIAN HOUSEHOLD DEPOSIT MARKET, 1992-1999

In our analysis of the Russian household deposit market during the 1990s, we show how the initial conditions of market emergence contributed to a vicious circle in which private commercial banks progressively lost the trust of potential depositors. The roots of this destructive dynamic lay in the initial conditions of market emergence. Initial experiences of fraud and financial loss led Russian households to distrust that commercial banks would honor their contractual obligations. As distrust grew and became more ingrained, the competitive conditions in the deposit market changed in a way that further increased the gains to opportunism and decreased the returns to trust production. In a self-reinforcing process, fraud begat more fraud.http://deepblue.lib.umich.edu/bitstream/2027.42/39974/3/wp588.pd

When and Why? A Critical Survey on Coordination Failure in the Laboratory

Coordination games with Pareto-ranked equilibria have attracted major theoretical attention over the past two decades. Two early path-breaking sets of experimental studies were widely interpreted as suggesting that coordination failure is a common phenomenon in the laboratory. We identify the major determinants that seem to affect the incidence, and/or emergence, of coordination failure in the lab and review critically the existing experimental studies on coordination games with Pareto-ranked equilibria since that early evidence emerged. We conclude that there are many ways to engineer coordination successes.coordination games, Pareto-ranked equilibria, payoff-asymmetric equilibria, staghunt games, optimization incentives, robustness, coordination, coordination failure

INSTITUTIONS AND THE VICIOUS CIRCLE OF DISTRUST IN THE RUSSIAN HOUSEHOLD DEPOSIT MARKET, 1992-1999

In our analysis of the Russian household deposit market during the 1990s, we show how the initial conditions of market emergence contributed to a vicious circle in which private commercial banks progressively lost the trust of potential depositors. The roots of this destructive dynamic lay in the initial conditions of market emergence. Initial experiences of fraud and financial loss led Russian households to distrust that commercial banks would honor their contractual obligations. As distrust grew and became more ingrained, the competitive conditions in the deposit market changed in a way that further increased the gains to opportunism and decreased the returns to trust production. In a self-reinforcing process, fraud begat more fraud.

Interactive rhythms across species: The evolutionary biology of animal chorusing and turn-taking

The study of human language is progressively moving toward comparative and interactive frameworks, extending the concept of turn‐taking to animal communication. While such an endeavor will help us understand the interactive origins of language, any theoretical account for cross‐species turn‐taking should consider three key points. First, animal turn‐taking must incorporate biological studies on animal chorusing, namely how different species coordinate their signals over time. Second, while concepts employed in human communication and turn‐taking, such as intentionality, are still debated in animal behavior, lower level mechanisms with clear neurobiological bases can explain much of animal interactive behavior. Third, social behavior, interactivity, and cooperation can be orthogonal, and the alternation of animal signals need not be cooperative. Considering turn‐taking a subset of chorusing in the rhythmic dimension may avoid overinterpretation and enhance the comparability of future empirical work

Dopamine and the Temporal Dependence of Learning and Memory

Animal behavior is largely influenced by the seeking out of rewards and avoidance of punishments. Positive or negative reinforcements, like a food reward or painful shock, impart meaningful valence onto sensory cues in the animal’s environment. The ability of animals to form associations between a sensory cue and a rewarding or punishing reinforcement permits them to adapt their future behavior to maximize reward and minimize punishments. Animals rely on the timing of events to infer the causal relationships between cues and outcomes –– sensory cues that precede a painful shock in time become associated with its onset and are imparted with negative valence, whereas cues that follow the shock in time are instead associated with its cessation and imparted with positive valence. While the temporal requirements for associative learning have been well characterized at the behavioral level, the molecular and circuit mechanisms for this temporal sensitivity remain incompletely understood. Using the simple architecture of the mushroom body, an olfactory associative learning center in Drosophila, I examined how the relative timing of olfactory inputs and dopaminergic reinforcement signals is encoded at the molecular, synaptic, and circuit level to give rise to learned odor associations. I show that in Drosophila, opposing olfactory associations can be formed and updated on a trial-by-trial basis depending on the temporal relationship between an odor cue and dopaminergic reinforcement during conditioning. Additionally, both negative and positive reinforcements equivalently instruct appetitive and aversive olfactory associations –– odors preceding a negative reinforcement or following a rewarding reinforcement acquire an aversive valence, while odors instead following a negative reinforcement or preceding a rewarding reinforcement become attractive. Furthermore, functional imaging revealed that synapses within the mushroom body are bidirectionally modulated depending on the temporal ordering of odor and dopaminergic reinforcement, leading to synaptic depression when an odor precedes dopaminergic activity or synaptic facilitation when dopaminergic activity instead precedes an odor. Through the synchronous recording of neural activity and behavior, I found that the bidirectional regulation of synaptic transmission within the mushroom body directly correlates with the emergence of learned olfactory behaviors. This temporal sensitivity arises from two dopamine receptors, DopR1 and DopR2, that couple to distinct second-messengers and direct either synaptic depression or potentiation. Loss of either receptor renders the synapses of the mushroom body capable of only unidirectional plasticity and prevents the behavioral flexibility of writing opposing associations depending on the temporal structure of conditioning. Together, these results reveal how the distinct intracellular signaling pathways of two dopamine receptors can detect the order of events within an associative learning circuit to instruct opposing forms of synaptic and behavioral plasticity, providing a mechanism for animals to use both the onset and offset of a reinforcement signal to instruct distinct associations. Additionally, this bidirectional modulation allows animals to flexibly update olfactory associations on a trial-bytrial basis when temporal relationships are altered, permitting them to contend with a complex and changing sensory world