"We study the stochastic dynamics of evolutionary games, and focus on the so-called `stochastic slowdown' effect, previously observed in (Altrock et. al, 2010) for simple evolutionary dynamics. Slowdown here refers to the fact that a beneficial mutation may take longer to fixate than a neutral one. More precisely, the fixation time conditioned on the mutant taking over can show a maximum at intermediate selection strength. We show that this phenomenon is present in the prisoner's dilemma, and also discuss counterintuitive slowdown and speedup in coexistence games. In order to establish the microscopic origins of these phenomena, we calculate the average sojourn times. This allows us to identify the transient states which contribute most to the slowdown effect, and enables us to provide an understanding of slowdown in the takeover of a small group of cooperators by defectors: Defection spreads quickly initially, but the final steps to takeover can be delayed significantly. The analysis of coexistence games reveals even more intricate behavior. In small populations, the conditional average fixation time can show multiple extrema as a function of the selection strength, e.g., slowdown, speedup, and slowdown again. We classify two-player games with respect to the possibility to observe non-monotonic behavior of the conditional average fixation time as a function of selection strength."

"Without mutation and migration, evolutionary dynamics ultimately leads to the extinction of all but one species. Such fixation processes are well understood and can be characterized analytically with methods from statistical physics. However, many biological arguments focus on stationary distributions in a mutation-selection equilibrium. Here, we address the equilibration time required to reach stationarity in the presence of mutation, this is known as the mixing time in the theory of Markov processes. We show that mixing times in evolutionary games have the opposite behaviour from fixation times when the intensity of selection increases: In coordination games with bistabilities, the fixation time decreases, but the mixing time increases. In coexistence games with metastable states, the fixation time increases, but the mixing time decreases. Our results are based on simulations and the WKB approximation of the master equation."

"We study the problem of reaching consensus in complex networks where each node knows nothing about the overall topology, other than its own neighbors. We assume that there exist a set of malicious or stubborn nodes in the network that do not follow the same dynamics as the rest of the nodes. When the normal nodes act on purely local information, previous work has established that standard graph notions such as connectivity are no longer sufficient to characterize the ability of the non-malicious nodes to reach agreement. Instead, the network must satisfy a property known as robustness. In this paper we investigate the robustness properties of common random graph models for complex networks, including the preferential attachment model, the Erdos-Renyi model, and the geometric random graph model. We show that these models exhibit a thresholding behavior for robustness. In particular, we show that the notions of connectivity and robustness coincide on various random graph models, indicating that purely local knowledge is sufficient when the objective is to reach agreement on an appropriate function of the initial values."

"In this paper we address the general question of how social influence determines collective outcomes for large populations of individuals faced with binary decisions. First, we define conditions under which the behavior of individuals making binary decisions can be described in terms of what we call an influence-response function: a one-dimensional function of the (weighted) number of individuals choosing each of the alternatives. And second, we demonstrate that, under the assumptions of global and anonymous interactions, general knowledge of the influence-response functions is sufficient to compute equilibrium, and even non-equilibrium, properties of the collective dynamics. By enabling us to treat in a consistent manner classes of decisions that have previously been analyzed separately, our framework allows us to find similarities between apparently quite different kinds of decision situations, and conversely to identify important differences between decisions that would otherwise appear very similar."

"Complex problems in science, business, and engineering typically require some tradeoff between exploitation of known solutions and exploration for novel ones, where, in many cases, information about known solutions can also disseminate among individual problem solvers through formal or informal networks. Prior research on complex problem solving by collectives has found the counterintuitive result that inefficient networks, meaning networks that disseminate information relatively slowly, can perform better than efficient networks for problems that require extended exploration. In this paper, we report on a series of 256 Web-based experiments in which groups of 16 individuals collectively solved a complex problem and shared information through different communication networks. As expected, we found that collective exploration improved average success over independent exploration because good solutions could diffuse through the network. In contrast to prior work, however, we found that efficient networks outperformed inefficient networks, even in a problem space with qualitative properties thought to favor inefficient networks. We explain this result in terms of individual-level explore-exploit decisions, which we find were influenced by the network structure as well as by strategic considerations and the relative payoff between maxima. We conclude by discussing implications for real-world problem solving and possible extensions."

"Few events in the history of humanity rival the Industrial Revolution. Following its onset in eighteenth-century Britain, sweeping changes in agriculture, manufacturing, transportation, and technology began to gain unstoppable momentum throughout Europe, North America, and eventually much of the world—with profound effects on socioeconomic and cultural conditions.
"In The Institutional Revolution, Douglas W. Allen offers a thought-provoking account of another, quieter revolution that took place at the end of the eighteenth century and allowed for the full exploitation of the many new technological innovations. Fundamental to this shift were dramatic changes in institutions, or the rules that govern society, which reflected significant improvements in the ability to measure performance—whether of government officials, laborers, or naval officers—thereby reducing the role of nature and the hazards of variance in daily affairs. Along the way, Allen provides readers with a fascinating explanation of the critical roles played by seemingly bizarre institutions, from dueling to the purchase of one’s rank in the British Army.
"Engagingly written, The Institutional Revolutiontraces the dramatic shift from premodern institutions based on patronage, purchase, and personal ties toward modern institutions based on standardization, merit, and wage labor—a shift which was crucial to the explosive economic growth of the Industrial Revolution."

Mostly economists?

Endorsed by Hodgson, but probably worth checking out anyway. "Covering a wide range of topics, including fads, public policy, the spread of religion, and herd behavior in markets, Alex Mesoudi shows that human culture is itself an evolutionary process that exhibits the key Darwinian mechanisms of variation, competition, and inheritance. This cross-disciplinary volume focuses on the ways cultural phenomena can be studied scientifically—from theoretical modeling to lab experiments, archaeological fieldwork to ethnographic studies—and shows how apparently disparate methods can complement one another to the mutual benefit of the various social science disciplines. Along the way, the book reveals how new insights arise from looking at culture from an evolutionary angle. Cultural Evolution provides a thought-provoking argument that Darwinian evolutionary theory can both unify different branches of inquiry and enhance understanding of human behavior."

Looks interesting, but of course the library doesn't subscribe, and sociologists apparently do not believe in PUTTING THEIR &#H!H% PAPERS ONLINE.  ETA: Thanks to reader F.B. for sending me a copy!

In a public form, at last.

"A general theory of top-down cascades in complex networks is described which explains two similar types of perturbation amplifications in the complex networks of business supply chains (the `bullwhip effect') and ecological food webs (trophic cascades). The dependence of the strength of the effects on the interaction strength and covariance in the dynamics as well as the graph structure allows both explanation and prediction of widely recognized effects in each type of system."

"problem of learning in repeated general-sum matrix games when a learning algorithm can observe the actions but not the payoffs of its associates. ... non-stationarity of the environment caused by learning associates in these games, most state-of-the-art algorithms perform poorly ... due to an inability to make profitable compromises.=,,, agent must effectively balance competing objectives, including bounding losses, playing optimally with respect to current beliefs, and taking calculated, but profitable, risks. ... we present ... M-Qubed, a reinforcement learning algorithm ... balancing best-response, cautious, and optimistic learning biases... learns to make profitable compromises across a wide-range of repeated matrix games played with many kinds of learners... average payoffs meet or exceed its maximin value in the limit.., in two-player games... average payoffs approach the value of the Nash bargaining solution... robust behavior in round-robin and evolutionary tournaments..."

The "to teach" tag is conditional...

" These findings underscore the fundamental difference between information spread and other contagion processes: despite multiple opportunities for infection within a social group, people are less likely to become spreaders of information with repeated exposure."

"Just as neurons interconnect in networks that create structured thoughts beyond the ken of any individual neuron, so people spontaneously organize themselves into groups to create emergent organizations that no individual may intend, comprehend, or even perceive. ... two experimental paradigms in which we attempt to build predictive bridges between the beliefs, goals, and cognitive capacities of individuals and patterns of behavior at the group level, showing how the members of a group dynamically allocate themselves to resources and how innovations diffuse through a social network. Agent-based computational models have provided useful explanatory and predictive accounts. Together, the models and experiments point to tradeoffs between exploration and exploitation—that is, compromises between individuals using their own innovations and using innovations obtained from their peers—and the emergence of group-level organizations..."

"In this paper we prove that the stationary distribution of populations in genetic algorithms focuses on the uniform population with the highest fitness value as the selective pressure goes to ∞ and the mutation probability goes to 0. The obtained sufficient condition is based on the work of Albuquerque and Mazza (2000), who, following Cerf (1998), applied the large deviation principle approach (Freidlin-Wentzell theory) to the Markov chain of genetic algorithms. The sufficient condition is more general than that of Albuquerque and Mazza, and covers a set of parameters which were not found by Cerf."

"challenges the conventional wisdom that participatory democracy is worthy in purpose but unworkable in practice... social movements have often used bottom-up decision making as a powerful tool for political change... also highlights the obstacles that arise when activists model their democracies after familiar nonpolitical relationships such as friendship, tutelage, and religious fellowship... brought into their deliberations the trust, respect, and caring typical of those relationships. But it has also fostered values that run counter to democracy ... exclusivity ... aversion to rules ... have been the fault lines ... the fragility of the form less to its basic inefficiency or inequity than to the gaps between activists' democratic commitments and the cultural models on which they have depended ... The challenge ... is to forge new kinds of democratic relationships, ones that balance trust with accountability, respect with openness to disagreement, and caring with inclusiveness."

"A novel paradigm was developed to study the behavior of groups of networked people searching a problem space. The authors examined how different network structures affect the propagation of information in laboratory-created groups. Participants made numerical guesses and received scores that were also made available to their neighbors in the network. The networks were compared on speed of discovery and convergence on the optimal solution. One experiment showed that individuals within a group tend to converge on similar solutions even when there is an equally valid alternative solution. Two additional studies demonstrated that the optimal network structure depends on the problem space being explored, with networks that incorporate spatially based cliques having an advantage for problems that benefit from broad exploration, and networks with greater long-range connectivity having an advantage for problems requiring less exploration."

The definition of "democracy" in the abstract strikes me as rather odd.

I really need to write up those notes on realism & social construction

"this book is about political culture. It examines developments in the social sciences and integrates them into a theoretical explanation of historical changes in political values. The starting point is the premise that political culture is rooted in the interaction between individual thinking and social norms. Through discourse, individual conceptions of social life are transformed and, interactively, social norms and cultural orientations as well. The first two parts of the book explore these issues theoretically. The second two examine them empirically by showing the ways that political cultures have changed over time. In the modern period the differences in the political cultures of capitalist and communist systems are contrasted; although both coneptualize social life in terms of property accumulation, they utilize different cultural orientations to reduce institutional transaction costs. The way the tensions between these two systems can be resolved is also explored."

"A model of “ephemeral” population structure is pre- sented that applies not only to biological systems in which discrete groups form but also to networks without group boundaries. The evolution of altruistic behaviors is discussed. Nonrandom interaction and nonlinear fitness structures are modeled; together, these factors can produce stable polymorphisms of altruistic and selfish types, as well as bistability. Empirical applications of the model may be found in microbes, marine invertebrates, annual plants, and other organisms."

"human-subject experiments on the problems of coloring (a social differentiation task) and consensus (a social agreement task) [on a network]. Both [are] coordination games, and despite their cognitive similarity, we find that ... network structure elicits opposing behavioral effects in the two problems, with increased long-distance connectivity making consensus easier for subjects and coloring harder. We investigate the influence that subjects have on their network neighbors and the collective outcome, and find that it varies considerably, beyond what can be explained by network position alone. ... strong correlations between influence and other features of individual subject behavior. ... much of the recent research in network science ... often emphasizes network topology out of the context of any specific problem and places primacy on network position, our findings highlight the potential importance of the details of tasks and individuals in social networks."

Unquestionably the most depressing thing I have ever cited.

Not sure of the relevance to the "re:" paper. "knowledge acquisition as performed by multiple agents interacting as they infer, under [noise], respective models of a complex system. ... at each time step, each agent takes into account its current observation as well as the average of the models of its neighbors. The agents are connected by a network... of Erdős-Rényi or Barabási-Albert type. .. [if] one [agent] has a different [error rate] (higher or lower). ... [t]he influence of this special agent over the quality of the models inferred by the rest of the network can be substantial, varying linearly with the ... degree of the [special] agent ... [if] the degree of this agent is taken as a respective fitness parameter, the effect of the different [error rate] is ... superlinear.. when the agents are grouped into communities ... edges between agents (within a community) having higher probability of observation error [worsens] the estimation of the agents in the other communities."

"Understanding under what conditions interacting populations, whether they be plants, animals, or viral particles, coexist... Both biotic interactions and environmental fluctuations ... can facilitate or disrupt coexistence. To better understand this interplay between these deterministic and stochastic forces, we develop a mathematical theory extending the nonlinear theory of permanence for deterministic systems to stochastic difference and differential equations. Our condition for coexistence requires that there is a fixed set of weights associated with the interacting populations and this weighted combination of populations' invasion rates is positive for any (ergodic) stationary distribution associated with a subcollection of populations. ... with] sufficient noise ... the populations approach a unique positive stationary distribution. ... coexistence criterion is robust to small perturbations of the model functions."

"Henrich and Boyd (2002) were the first to propose a formal model of the role of attraction in cultural evolution. They came to the surprising conclusion that, when both attaction and selection are at work, final outcomes are determined by selection alone. This result is based on a determistic view of cultural attraction, different from the probabilistic view introduced in Sperber (1996). We defend this probabilistic view, show how to model it, and argue that, when both attraction and selection are at work, both affect final outcomes."

"A hitherto neglected form of explanation is explored, especially its role in population genetics. “Statistically abstractive explanation” (SA explanation) mandates the suppression of factors probabilistically relevant to an explanandum when these factors are extraneous to the theoretical project being pursued. When these factors are suppressed, the explanandum is rendered uncertain. But this uncertainty traces to the theoretically constrained character of SA explanation, not to any real indeterminacy. Random genetic drift is an artifact of such uncertainty, and it is therefore wrong to reify it as a cause of evolution or as a process in its own right."

"Sociological studies of culture have made significant progress on conceptual clarification of the concept, [but not] on questions of measurement. This study empirically examines internal conflicts (or “infighting”), a ubiquitous phenomenon in political organizing, to propose a “resinous culture framework” that holds promise for redirection. The data comprise 674 newspaper articles and more than 100 archival documents that compare internal dissent across two previously unstudied lesbian and gay Marches on Washington. Analyses reveal that activists use infighting as a vehicle to engage in otherwise abstract definitional debates that provide concrete answers to questions such as who are we and what do we want. The mechanism that enables infighting to concretize these cultural concerns is its coupling with fairly mundane and routine organizational tasks."

"all institutions are syncretic, ... composed of an indeterminate number of features, which are decomposable and recombinable in unpredictable ways. ... action within institutions is always potentially creative, ... draw[ing] on [many] cultural and institutional resources to create novel combinations. [This is] creative syncretism. ... existing accounts of institutional change, which are rooted in structuralism, produce excess complexity and render the most important sources and results of change invisible. ... we need [to explain] how people live institutional rules. We find that grounding in John Dewey’s pragmatist theory of habit. ... a field guide to creative syncretism. It uses an experiential approach to provide novel insights on three problems that have occupied institutionalist research: periodization in American political development, convergence among advanced capitalist democracies, and institutional change in developing countries."

""The number of available ideas [about society and morals] seems limited rather than infinite. If there is one well-established law in the field known as the History of Ideas, it is that whatever has been said has also been said by someone else on an earlier occasion. Although a certain relative originality is possible, it is largely a matter of the combination of primary ideas and of context. The ledger already seems to contain very nearly all possible ideas, and the unsatisfactoriness of that tacit sociology which is half incapsulated in the history of social ideas lies in the fact that it seems to explain what people do in terms of what some thinker said or wrote. But, as all the ideas are in effect ever-present, the problem is rather why some of them acquire a powerful appeal at a given time."

"The joint dynamics of population-level social institutions and individual preferences (or more broadly cultures) are illustrated in four case studies: the end of Communist Party rule in the German Democratic Republic, the transformation of traditional contracts governing agricultural work in the Philippines, the demise of Apartheid in South Africa, and the spread and retreat of female genital cutting in West Africa. A stochastic evolutionary game model of the underlying processes captures five interrelated aspects of real world historical dynamics: its often bottom- up and decentralized nature, the complementarity between cultural and institutional dynamics, the long term persistence of inefficient institutions, the often revolutionary nature of institutional and cultural change and the prominent role of technical change in the process of institutional and cultural innovation." --- Do I detect, comrades, in that last sentence, an echo of "in the last instance"?

I'm pretty impressed.

Review: http://bactra.org/reviews/ober-democracy-and-knowledge.html

When does culture help you realize that not only is it not raining, but that in fact somebody's pissing on you and a lot of other people?

"Considers the question of how liberal democracies produce citizens who are capable of governing themselves, rethinking the relationship between welfare and citizenship, democracy and despotism, and subjectivity and subjection."