trackr: A Framework for Enhancing Discoverability and Reproducibility of Data Visualizations and Other Artifacts in R

Research is an incremental, iterative process, with new results relying and building upon previous ones. Scientists need to find, retrieve, understand, and verify results in order to confidently extend them, even when the results are their own. We present the trackr framework for organizing, automatically annotating, discovering, and retrieving results. We identify sources of automatically extractable metadata for computational results, and we define an extensible system for organizing, annotating, and searching for results based on these and other metadata. We present an open-source implementation of these concepts for plots, computational artifacts, and woven dynamic reports generated in the R statistical computing language

The Effect of Improvements in Health and Longevity on Optimal Retirement and Saving

We develop a life-cycle model of optimal retirement and savings behavior under complete markets where retirement is caused by worsening health in old age. Our model explains the long-run decline in the age of retirement as an income level effect. We show that improvements in health and longevity tend to increase the desired retirement age, though less than proportionately, while, contrary to conventional views, reducing savings rates. The retirement age is not simply proportional to healthy lifespan because compound interest creates a wealth effect when lifespan increases, leading to more leisure (early retirement) and higher consumption (lower savings).Health, longevity, savings, retirement

The Effect of Improvements in Health and Longevity on Optimal Retirement and Saving

We develop a life-cycle model of optimal retirement and savings behavior under complete markets where retirement is caused by worsening health in old age. Our model explains the long-run decline in the age of retirement as an income level effect. We show that improvements in health and longevity tend to increase the desired retirement age, though less than proportionately, while, contrary to conventional views, reducing savings rates. The retirement age is not simply proportional to healthy life span because compound interest creates a wealth effect when lifespan increases, leading to more leisure (early retirement) and higher consumption (lower savings).

A Theory of Retirement

We construct a life-cycle model in which retirement occurs at the end of life as a result of declining health. We show that improvements in life expectancy, coupled with a delay in the onset of disability, increases both the optimal consumption level and the proportion of life spent in leisure. The retirement age increases proportionally less than the increase in life expectancy.aging, health, retirement, savings

Logarithmic terms in entanglement entropies of 2D quantum critical points and Shannon entropies of spin chains

Universal logarithmic terms in the entanglement entropy appear at quantum critical points (QCPs) in one dimension (1D) and have been predicted in 2D at QCPs described by 2D conformal field theories. The entanglement entropy in a strip geometry at such QCPs can be obtained via the "Shannon entropy" of a 1D spin chain with open boundary conditions. The Shannon entropy of the XXZ chain is found to have a logarithmic term that implies, for the QCP of the square-lattice quantum dimer model, a logarithm with universal coefficient $\pm 0.25$. However, the logarithm in the Shannon entropy of the transverse-field Ising model, which corresponds to entanglement in the 2D Ising conformal QCP, is found to have a singular dependence on replica or R\'enyi index resulting from flows to different boundary conditions at the entanglement cut.Comment: 4 pages and 4 page appendix, 4 figure

Demographic Change, Social Security Systems, and Savings

In theory, improvements in healthy life expectancy should generate increases in the average age of retirement, with little effect on savings rates. In many countries, however, retirement incentives in social security programs prevent retirement ages from keeping pace with changes in life expectancy, leading to an increased need for life-cycle savings. Analyzing a cross-country panel of macroeconomic data, we find that increased longevity raises aggregate savings rates in countries with universal pension coverage and retirement incentives, though the effect disappears in countries with pay-as-you-go systems and high replacement rates

THE PROFITABILITY OF AGRICULTURAL CUSTOMERS FOR COMMERCIAL BANKS IN THE SOUTHEAST

Agricultural Finance,

Towards a Principled Representation of Discourse Plans

We argue that discourse plans must capture the intended causal and decompositional relations between communicative actions. We present a planning algorithm, DPOCL, that builds plan structures that properly capture these relations, and show how these structures are used to solve the problems that plagued previous discourse planners, and allow a system to participate effectively and flexibly in an ongoing dialogue.Comment: requires cogsci94.sty, psfig.st