Sharing, Gift-Giving, and Optimal Resource Use Incentives in Hunter-Gatherer Society

In the typical hunter-gatherer society, decision-making is collective, yet decentralized, access to resources is shared, goods are typically distributed via reciprocal exchange, sharing, and gift-giving, and the distribution of both income and decision-making power is egalitarian. We argue these features are interrelated. We adopt an incentive-based view of sharing and gift-giving, in which the fundamental role of sharing and gift-giving is to implement socially desirable production decisions in the face of a common resource use problem. We show how this system decentralizes decision-making, while at the same time encouraging agents to make production decisions in the best interests of the group. Sharing rules give agents optimal use incentives, while gift-giving obligations give agents incentives to reveal private information about skill. The system has some interesting properties; for example, it may result in a relatively equal distribution of income, even though the productive capabilities of agents differ. Our theory is also able to account for some features of the ethnographic record that do not jibe well with existing theories of sharing; for example, why the rather extensive free-riding on the efforts of the most productive agents is typically tolerated in hunter-gatherer society.

Marriage, Specialization, and the Gender Division of Labor

A customary gender division of labor is one in which women and men are directed towards certain tasks and/or explicitly prohibited from performing others. We offer an explanation as to why the gender division of labor is so often enforced by custom, and why customary gender divisions of labor generally involve both direction and prohibition. Our model builds on the literature on the marital hold-up problem, and considers both problems in choice of specialty and human capital acquisition in a framework in which agents learn a variety of skills and must search for a marriage partner on the marriage market. We show that wasteful behavior may emerge due to strategic incentives in career choice and human capital acquisition, and that both problems may be mitigated through the customary gender division of labor. We find, however, that a gender division of labor is not Pareto-improving; one gender is made worse off. Both the distributional effects and welfare gains to a customary gender division of labor decrease as opportunities to exchange in markets increase.

Kings and Vikings: On the Dynamics of Competitive Agglomeration

This paper studies the Viking age – the roughly 300 year period beginning in 800 AD – from the perspective of the economics of conflict. The Viking age is interesting because throughout the time period, the scale of conflict increased – small scale raiding behaviour eventually evolved into large scale clashes between armies. With this observation in mind, we present a theoretical model describing the incentives both the defending population and the invading population had to agglomerate into larger groups to better defend against attacks, and engage in attacks, respectively. The result is what might be called a theory of competitive agglomeration. We also apply our model in assessing the factors behind the onset of Vikings raids at the end of the 8th century.

A Human Capital-Based Theory of Post Marital Residence Rules

In pre-modern societies the residence of a newly-wedded couple is often decided by custom. We formulate a theory of optimal post-marital residence rules based on contracting problems created by the nature of pre-marriage human capital investments. We argue that a fixed post-marital residence rule may mitigate a hold-up problem by specifying marriage terms and limiting possibilities for renegotiation; the trade-off is that the rule may prohibit beneficial renegotiation of post-marital location. A point of interest of our approach is that the magnitude and direction of transfers accompanying marriage are endogenous. We apply our theoretical results to understanding cross-cultural post-marital residence patters. We find some predictive ability in variables related to outside options, control over the environment, and potential degree of social control.Marriage, Bargaining, Hold-up Problem, Dowry, Bride-Price

A Human Capital-Based Theory of Post-Marital Residence Rules

In pre-modern societies the residence of a newly-wedded couple is often decided by custom. While researchers have analyzed factors leading to particular post-marital residence patterns, no one has explained why a society should have a customary rule in the first place. Our theory stems from contracting problems created by the nature of pre-marriage human capital investments. We argue that a fixed post-marital residence rule may solve a hold-up problem by specifying marriage terms and limiting possibilities for renegotiation; the trade-off is the rule may prohibit beneficial renegotiation of post-marital location. We compare alternative residence rules (or lack thereof) under different degrees of location specificity of human capital and environmental uncertainty. We apply our theoretical results to Murdock's (1967) 862-society data set, augmented with climate data. We find some predictive ability in variables related to outside options, control over the environment, and potential degree of social control.

Court Decisions and Equity Markets: Estimating the Value of Copyright Protection

We use a novel database on U. S. federal court decisions to measure the changes in the state of copyright protection in both statute and case law. We combine an index of copyright breadth derived from this database with a quarterly panel of firms in creative industries over the years 1986-1998. Using this data, we measure the impact of changes in the breadth of copyright on the market valuation of firm equity. We maintain the assumption that equity markets will incorporate the value of copyright innovations into the price of equity. After controlling for a variety of fundamental determinants of ¯rm-level excess returns to equity, we find that a court case broadening copyright is associated with a statistically significant 23-45 basis points increase in a firm's excess return. Our results obtain across both 4-5 year sub-samples and the size distribution of firms.

Marriage, Specialization, and the Gender Division of Labor

A customary gender division of labor is one in which women and men are directed towards certain tasks and/or explicitly prohibited from performing others. We offer an explanation as to why the gender division of labor is so often enforced by custom, and why customary gender divisions of labor generally involve both direction and prohibition. Our model builds on the literature on the marital hold-up problem, and considers both problems in choice of specialty and human capital acquisition in a framework in which agents learn a variety of skills and then enter the marriage market. We show that wasteful behavior may emerge due to strategic incentives in career choice and human capital acquisition, and that both problems may be mitigated through the customary gender division of labor. We find, however, that a gender division of labor is not Pareto-improving; one gender is made worse off. Both the distributional effects and welfare gains of a customary gender division of labor decrease as opportunities to exchange in markets increase.earnings inequality, income inequality, gender, race, and ethnicity differences

Simulation and inference algorithms for stochastic biochemical reaction networks: from basic concepts to state-of-the-art

Stochasticity is a key characteristic of intracellular processes such as gene regulation and chemical signalling. Therefore, characterising stochastic effects in biochemical systems is essential to understand the complex dynamics of living things. Mathematical idealisations of biochemically reacting systems must be able to capture stochastic phenomena. While robust theory exists to describe such stochastic models, the computational challenges in exploring these models can be a significant burden in practice since realistic models are analytically intractable. Determining the expected behaviour and variability of a stochastic biochemical reaction network requires many probabilistic simulations of its evolution. Using a biochemical reaction network model to assist in the interpretation of time course data from a biological experiment is an even greater challenge due to the intractability of the likelihood function for determining observation probabilities. These computational challenges have been subjects of active research for over four decades. In this review, we present an accessible discussion of the major historical developments and state-of-the-art computational techniques relevant to simulation and inference problems for stochastic biochemical reaction network models. Detailed algorithms for particularly important methods are described and complemented with MATLAB implementations. As a result, this review provides a practical and accessible introduction to computational methods for stochastic models within the life sciences community

Mergers with Quality Differentiated Products

We consider the impact of merger on the equilibrium price and quality of products. Consumer demand for both products depends not only on own price and quality, but also on the price and quality of the other product. We consider both the case in which the merging firms produce gross complements, and the case in which the firms produce gross substitutes. In both cases, merger may lower or increase both product price and quality. In the case in which firms produce complementary products, it may happen that firms both lower price and increase product quality when merged. This happens when the cross quality elasticities of demand and the cross price elasticities of demand are equal in magnitude. Surprisingly, we also find that there are situations under which merger between firms producing substitutes increases welfare. For example, it is possible that merger between firms producing gross complements may result in higher product quality but lower social welfare, and merger between firms producing substitute products may result in lower product quality but higher social welfare.

Adaptive Markov Chain Monte Carlo Sampling and Estimation in Mata

I describe algorithms for drawing from distributions using adaptive Markov chain Monte Carlo (MCMC) methods, introduce a Mata function for performing adaptive MCMC, amcmc(), and a suite of functions amcmc *() allowing an alternative implementation of adaptive MCMC. amcmc() and amcmc *() may be used in conjunction with models set up to work with Mata\u27s [M-5] moptimize( ) or [M-5] optimize( ), or with stand-alone functions. To show how the routines might be used in estimation problems, I give two examples of what Chernozukov and Hong (2003) refer to as Quasi-Bayesian or Laplace-Type estimators - simulation-based estimators employing MCMC sampling. In the first example I illustrate basic ideas and show how a simple linear model can be estimated by simulation. In the next example, I describe simulation-based estimation of a censored quantile regression model following Powell (1986); the discussion describes the workings of the Stata command mcmccqreg. I also present an example of how the routines can be used to draw from distributions without a normalizing constant, and in Bayesian estimation of a mixed logit model. This discussion introduces the Stata command bayesmlogit