I n all areas of scientific inquiry, the ideas that researchers pursue are constrained by the methods available to them. thankfully, new and generative methodological paradigms are frequently born, often directly as a result of scientists’ own ingenuity. two prominent examples in psychology include thurstone’s (1928) insight that attitudes can be measured, a revelation that served as the founda...

Recent literature suggests that the increasingly blurred relationship between paid employment and retirement facilitates a retirement transition period, a life course stage, which may involve a change of residence. The role of such pre-retirement age mobility in the repopulation of rural areas has, however, received relatively little academic scrutiny. This paper draws upon findings from a two-...

In this paper I study conditions for the emergence of cooperative behavior in a dynamic model of population interaction. The model has finitely many individuals located on a circle. The pay-off of each individual is partly based on the (local) interaction with neighbors and partly on (uniform) interaction with the whole population. The dynamics is driven by imitative behavior. I show that for a...

Since the late 1990s, scores of American cities have witnessed the re-emergence of large-scale homeless encampments for the first time since the Great Depression. Commonly portrayed as rooted in the national economic downturn and functionally undifferentiated, this paper demonstrates that large-scale encampments are rather shaped by urban policies and serve varied and even contradictory roles i...

We consider an interaction between a donor and a recipient where the actions of a donor produce multiple results to the recipient. There are Optimists and Pessimists who focus on the best and worst outcomes among them as a recipient of the interaction, respectively, and they try to reflect on their experience in their next action as a donor. What is the effect on the emergence of cooperation? T...

Over the past couple of decades, virtual humans have been attracting more and more attention. Many applications including, video games, movies, and various training and tutoring systems have benefited from work in this area. While the visual quality of virtual agents has improved dramatically, their intelligence and socialization still needs improvement. In this paper, we present work towards e...

Unified Growth Theory uncovers the forces that contributed to the existence of multiple growth regimes and the emergence of convergence clubs. It suggests that differential timing of take-offs from stagnation to growth segmented economies into three fundamental regimes: slow growing economies in a Malthusian regime, fast growing countries in a sustained growth regime, and economies in the trans...

A salient feature of globalization in recent decades is the emergence of “global supply chains” in which different countries specialize in different stages of a sequential production process. In Arnaud Costinot, Jonathan Vogel and Su Wang (2011), CVW hereafter, we have developed a simple theory of trade with sequential production to shed light on how global supply chains affect the interdepende...

Protandry is the emergence or arrival into a seasonal population of males before females and is widespread among both plants and animals. Conceptually, protandry should be subject to stabilizing selection because early emerging males risk death before mating and late-emerging males miss opportunities to mate. However, for any given male, the optimal emergence time may depend upon the mean and d...

To understand the collective spiking activity in neuronal populations, it is essential to reveal basic circuit variables responsible for these emergent functional states. Here, I develop a mean field theory for the population coupling recently proposed in the studies of visual cortex of mouse and monkey, relating the individual neuron activity to the population activity, and extend the original...