Social learning and information sharing: an evolutionary simulation model of foraging in Norway rats

Social learning is distinguished from innate behaviour and individual learning as a behavioural strategy. We investigate simple mechanisms for social learning in an evolutionary simulation of food-preference copying in Norway rats. These animals learn preferences by interacting with conspecifics, but, unexpectedly, they fail to learn aversions after interacting with a poisoned demonstrator. They also follow each other for food sites. Simulation results show that failure to discriminate between sick and healthy demonstrators may be due to food toxicity in foraging environments. A seemingly complex instance of social information transmission is explained through the action of simple behaviours in an appropriately structured environment

A Note on Adapting Propensity Score Matching and Selection Models to Choice Based Samples

The probability of selection into treatment plays an important role in matching and selection models. However, this probability can often not be consistently estimated, because of choice-based sampling designs with unknown sampling weights. This note establishes that the selection and matching procedures can be implemented using propensity scores fit on choice-based samples with misspecified weights, because the odds ratio of the propensity score fit on the choice-based sample is monotonically related to the odds ratio of the true propensity scores.choice-based sampling, matching models, propensity scores, selection models

Time variation in the inflation passthrough of energy prices

From Bayesian estimates of a vector autoregression (VAR) which allows for both coefficient drift and stochastic volatility, we obtain the following three results. First, beginning in approximately 1975, the responsiveness of core inflation to changes in energy prices in the United States fell rapidly and remains muted. Second, this decline in the passthrough of energy inflation to core prices has been sustained through a recent period of markedly higher volatility of shocks to energy inflation. Finally, reduced energy inflation passthrough has persisted in the face of monetary policy which quickly became less responsive to energy inflation starting around 1985.

Fifty Years of Mincer Earnings Regressions

The Mincer earnings function is the cornerstone of a large literature in empirical economics. This paper discusses the theoretical foundations of the Mincer model and examines the empirical support for it using data from Decennial Censuses and Current Population Surveys. While data from 1940 and 1950 Censuses provide some support for Mincer's model, data from later decades are inconsistent with it. We examine the importance of relaxing functional form assumptions in estimating internal rates of return to schooling and of accounting for taxes, tuition, nonlinearity in schooling, and nonseparability between schooling and work experience. Inferences about trends in rates of return to high school and college obtained from our more general model differ substantially from inferences drawn from estimates based on a Mincer earnings regression. Important differences also arise between cohort-based and cross-sectional estimates of the rate of return to schooling. In the recent period of rapid technological progress, widely used cross-sectional applications of the Mincer model produce dramatically biased estimates of cohort returns to schooling. We also examine the implications of accounting for uncertainty and agent expectation formation. Even when the static framework of Mincer is maintained, accounting for uncertainty substantially affects the return estimates. Considering the sequential resolution of uncertainty over time in a dynamic setting gives rise to option values, which fundamentally changes the analysis of schooling decisions. In the presence of sequential resolution of uncertainty and option values, the internal rate of return - a cornerstone of classical human capital theory - is not a useful guide to policy analysis.

EARNINGS FUNCTIONS AND RATES OF RETURN

The internal rate of return to schooling is a fundamental economic parameter that is often used to assess whether expenditure on education should be increased or decreased. This paper considers alternative approaches to estimating marginal internal rates of return for different schooling levels. We implement a general nonparametric approach to estimate marginal internal rates of return that take into account tuition costs, income taxes and nonlinearities in the earnings-schooling-experience relationship. The returns obtained by the more general method differ substantially from Mincer returns in levels and in their evolution over time. They indicate relatively larger returns to graduating from high school than from graduating from college, although both have been increasing over time.

Earnings Functions, Rates of Return and Treatment Effects: The Mincer Equation and Beyond

This paper considers the interpretation of "Mincer rates of return." We test and reject the Mincer model. It fails to track the time series of true returns. We show how repeated cross section and panel data improves the ability of analysts to estimate the ex ante and ex post marginal rate of returns. Accounting for sequential revelation of information calls into question the validity of the internal rate of return as a tool for policy analysis. The large estimated psychic costs of schooling found in recent work helps to explain why persons do not attend school even though the financial rewards for doing so are high. We present methods for computing distributions of ex post and ex ante returns.

Two New Proofs of Afriat's Theorem

We provide two new, simple proofs of Afriat's celebrated theorem stating that a finite set of price-quantity observations is consistent with utility maximization if, and only if, the observations satisfy a variation of the Strong Axiom of Revealed Preference known as the Generalized Axiom of Revealed Preference.Afriat's theorem, SARP, GARP

Earnings Functions and Rates of Return

The internal rate of return to schooling is a fundamental economic parameter that is often used to assess whether expenditure on education should be increased or decreased. This paper considers alternative approaches to estimating marginal internal rates of return for different schooling levels. We implement a general nonparametric approach to estimate marginal internal rates of return that take into account tuition costs, income taxes and nonlinearities in the earnings-schooling-experience relationship. The returns obtained by the more general method differ substantially from Mincer returns in levels and in their evolution over time. They indicate relatively larger returns to graduating from high school than from graduating from college, although both have been increasing over time.schooling, marginal internal rate of return, nonparametric estimation