Is the political business cycle for real?

This paper's macroeconomic model combines features from both real and political business cycle models. It augments a standard real business cycle tax model by allowing for varying levels of government partisanship and competence in order to replicate two important empirical regularities: First, that on average the economy expands early under Democratic presidents and contracts early under Republican presidents. Second, that presidents whose parties successfully retain the presidency have stronger-than-average growth in the second half of their terms. The model generates both of these features in conformity with U.S. post-World War II data.Business cycles

Optimal phosphorus loading for a potentially eutrophic lake

dynamic programming;sustainable development;ecology

Is the Political Business Cycle for Real?

This paper constructs and examines a macroeconomic model which combines features from both real and political business cycle models. We augment a standard real business cycle tax model by allowing for varying levels of government partisanship and competence in order to replicate two important empirical regularities: First, that on average the economy expands early under Democratic Presidents and contracts early under Republican Presidents. Second, that Presidents whose parties successfully retain the presidency have stronger than average growth in the second half of their terms. The model generates both of these features that conform to U.S. Post World War II data.Political business cycle

Quick X-ray Reflectivity using Monochromatic Synchrotron Radiation for Time-Resolved Applications

We describe and demonstrate a new technique for parallel collection of x-ray reflectivity data, compatible with monochromatic synchrotron radiation and flat substrates, and apply it to the in-situ observation of thin-film growth. The method employs a polycapillary x-ray optic to produce a converging fan of radiation incident onto a sample surface, and an area detector to simultaneously collect the XRR signal over an angular range matching that of the incident fan. Factors determining the range and instrumental resolution of the technique in reciprocal space, in addition to the signal-to-background ratio, are described in detail. Our particular implementation records $\sim$5\degree{} in $2\theta$ and resolves Kiessig fringes from samples with layer thicknesses ranging from 3 to 76 nm. Finally, we illustrate the value of this approach by showing in-situ XRR data obtained with 100 ms time resolution during the growth of epitaxial \ce{La_{0.7}Sr_{0.3}MnO3} on \ce{SrTiO3} by Pulsed Laser Deposition (PLD) at the Cornell High Energy Synchrotron Source (CHESS). Compared to prior methods for parallel XRR data collection, ours is the first method that is both sample-independent and compatible with highly collimated, monochromatic radiation typical of 3rd generation synchrotron sources. Further, our technique can be readily adapted for use with laboratory-based sources.Comment: Accepted in Journal of Synchrotron Radiatio

A Dynamic Structural Model for Stock Return Volatility and Trading Volume

This paper seeks to develop a structural model that lets data on asset returns and trading volume speak to whether volatility autocorrelation comes from the fundamental that the trading process is pricing or, is caused by the trading process itself. Returns and volume data argue, in the context of our model, that persistent volatility is caused by traders experimenting with different beliefs based upon past profit experience and their estimates of future profit experience. A major theme of our paper is to introduce adaptive agents in the spirit of Sargent (1993) but have them adapt their strategies on a time scale that is slower than the time scale on which the trading process takes place. This will lead to positive autocorrelation in volatility and volume on the time scale of the trading process which generates returns and volume data. Positive autocorrelation of volatility and volume is caused by persistence of strategy patterns that are associated with high volatility and high volume. Thee following features seen in the data: (i) The autocorrelation function of a measure of volatility such as squared returns or absolute value of returns is positive with a slowly decaying tail. (ii) The autocorrelation function of a measure of trading activity such as volume or turnover is positive with a slowly decaying tail. (iii) The cross correlation function of a measure of volatility such as squared returns is about zero for squared returns with past and future volumes and is positive for squared returns with current volumes. (iv) Abrupt changes in prices and returns occur which are hard to attach to 'news.' The last feature is obtained by a version of the model where the Law of Large Numbers fails in the large economy limit.

The (After) Life-Cycle Theory of Religious Contributions

We construct and estimate an economic model of religious giving. We employ a dynamic consumer optimization model with mortality in which intra-temporal utility stems from both consumption and religious contributions. Individuals also decide how to allocate resources between religious contributions (which have both a this-life consumption value and an after-life investment value) and other consumption expenditures. If religious contributions do not have an after-life investment value, the ratio of contributions to consumption expenditures should be unrelated to the probability of death. However, if there is an investment value from religious giving, individuals should allocate a greater share of their income to religious contributions as their probability of death increases. We estimate the model using data from the Consumer Expenditure Survey on the consumption and religious contribution patterns of a repeated cross-section of households and of a synthetic cohort panel. We find strong evidence that individuals behave as if religious contributions have a value in the after-life, in a manner consistent with the after life-cycle model. The estimates of the structural parameters of the model also imply that while after-life investment considerations (i.e. impending death) are an important determinant of the life-cycle profile of religious contributions, within-life (i.e. religious consumption) factors pin down a household’s average level of religious contributions over a lifetime.god, life-cycle, consumption, religion, tithing

Terrorism From Within: An Economic Model of Terrorism

In this paper, we develop and explore the implications of an economic model that links the incidence of terrorism in a country to the economic circumstances facing that country. We briefly sketch out a theory, in the spirit of Tornell (1998), that describes terrorist activities as being initiated by groups that are unhappy with the current economic status quo, yet unable to bring about drastic political and institutional changes that can improve their situation. Such groups with limited access to opportunity may find it rational to engage in terrorist activities. The result is then a pattern of reduced economic activity and increased terrorism. In contrast, an alternative environment can emerge where access to economic resources is more abundant and terrorism is reduced. Our empirical results are consistent with the theory. We find that for democratic, high income countries, economic contractions (i.e. recessions) can provide the spark for increased probabilities of terrorist activities.Growth; Terrorism; Political Economy

Opsin expression predicts male nuptial color in threespine stickleback.

Theoretical models of sexual selection suggest that male courtship signals can evolve through the build-up of genetic correlations between the male signal and female preference. When preference is mediated via increased sensitivity of the signal characteristics, correlations between male signal and perception/sensitivity are expected. When signal expression is limited to males, we would expect to find signal-sensitivity correlations in males. Here, we document such a correlation within a breeding population of threespine stickleback mediated by differences in opsin expression. Males with redder nuptial coloration express more long-wavelength-sensitive (LWS) opsin, making them more sensitive to orange and red. This correlation is not an artifact of shared tuning to the optical microhabitat. Such correlations are an essential feature of many models of sexual selection, and our results highlight the potential importance of opsin expression variation as a substrate for signal-preference evolution. Finally, these results suggest a potential sensory mechanism that could drive negative frequency-dependent selection via male-male competition and thus maintain variation in male nuptial color