Firm leverage, household leverage and the business cycle

This paper develops a macroeconomic model of the interaction between consumer debt and firm debt over the business cycle. I incorporate interest rate spreads generated by firm and household loan default risk into a real business cycle model. I estimate the model on US aggregate data. This allows me to analyse the quantitative importance of possible feedback effects between the debt levels of firms and households, and the relative contributions of financial and supply shocks to economic fluctuations. While firm level credit market frictions significantly amplify the response of investment to shocks, they do not amplify output responses. In general equilibrium, higher external financing spreads for households contribute to lower external financing spreads for firms, contrary to traditional Keynesian predictions. Furthermore, total factor productivity shocks remain an important source of business cycles in my model. They are responsible for 71 - 74% of the variance of output and 56 - 69% of the variance of consumption in the model. Financial shocks are important in explaining interest rate spreads and leverage ratios, but they account for less than 11% of the fluctuations in output. My results suggest that other factors, beyond credit market frictions on their own, are necessary to justify an important role for financial shocks in aggregate output fluctuations.Financial frictions; external finance premium; DSGE models; Bayesian estimation; business cycles

Hecke Modules from Metaplectic Ice

We present a new framework for a broad class of affine Hecke algebra modules, and show that such modules arise in a number of settings involving representations of $p$-adic groups and $R$-matrices for quantum groups. Instances of such modules arise from (possibly non-unique) functionals on $p$-adic groups and their metaplectic covers, such as the Whittaker functionals. As a byproduct, we obtain new, algebraic proofs of a number of results concerning metaplectic Whittaker functions. These are thus expressed in terms of metaplectic versions of Demazure operators, which are built out of $R$-matrices of quantum groups depending on the cover degree and associated root system

A New Compactification for Celestial Mechanics

This is an exposition of a new compactification of Euclidean space enabling the study of trajectories at and approaching spatial infinity, as well as results obtained for polynomial differential systems and Celestial Mechanics. The Lorenz system has an attractor for all real values of its parameters, and almost all of the complete quadratic systems share an interesting feature with the Lorenz system.;Informed by these results, the main theorem is established via a contraction mapping arising from an integral equation derived from the Celestial Mechanics equations of motion. We establish the existence of an open set of initial conditions through which pass solutions without singularities, to Newton\u27s gravitational equations in Euclidean space on a semi-infinite interval in forward time, for which every pair of particles separates like a multiple of time, as time tends to infinity. The solutions are constructible as series with rapid uniform convergence and their asymptotic behavior to any order is prescribed. We show that this family of solutions depends on 6N parameters subject to certain constraints. This confirms the logical converse of Chazy\u27s 100-year old result assuming solutions exist for all time, they take the form given by Bohlin: solutions of Bohlin\u27s form do exist for all time. An easy consequence not found elsewhere is that the asymptotic directions of many configurations exiting the universe depend solely on the initial velocities and not on their initial positions.;The N-body problem is fundamental to astrodynamics, since it is an idealization to point masses of the general problem of the motion of gravitating bodies, such as spacecraft motion within the Solar System. These new trajectories model paths of real particles escaping to infinity. A particle escaping its primary on a hyperbolic trajectory in the Kepler problem is the simplest example. This work may have relevance to new interplanetary trajectories or insight into known trajectories for potential space missions

Decision Making by Patients Awaiting Kidney Transplant

Involving patients in medical decisions by acknowledging patients personal values and individual preferences has become an important goal of providing ethical medical care. Despite a general movement towards a model of shared decision-making, many patients do not fully meet their preferred role in practice. The decision whether or not to accept a kidney once it is offered to a patient awaiting transplant has historically been made predominantly by the transplant surgeon with little involvement from the patient. Because dialysis can provide long-term renal replacement, declining a kidney is a viable option. Patient changes over time and inherent heterogeneity of donor kidneys make this an authentic decision requiring careful analysis of costs and benefits from the patient perspective. The purpose of this study is to improve our understanding of how patients and transplant surgeons prioritize different factors when deciding whether or not to accept a kidney that has become available, in order to empower patients to become more involved in the decision-making process. Phase I: We developed a comprehensive list of factors that patients might consider important through qualitative interviews with patients, and deliberation with a transplant surgeon (SK) and a transplant nephrologists (RF). Phase II: We quantified the relative importance of each factor for patients on the transplant list and for transplant surgeons with a computerized survey using Maximum Differences Scaling. We developed relative importance scores using Heirarchical Bayes analysis, and tested for associations between patient characteristics and relative importance scores using Spearmans correlation coefficient and the Mann Whitney U test for continuous and categorical variables respectively. Of the factors evaluated, patients placed the greatest value on Kidney quality, How closely matched you are to the kidney, and How strongly your surgeon feels you should accept the kidney. Relative importance of different factors did not change based on patient demographic characteristics. Patients who are on the waiting list longer give less importance to kidney quality (standard beta estimate -0.23, p value 0.03) and more importance to How difficult it is for you to be matched to a donor (ie whether or not you are sensitized) (standard beta estimate 0.28, p value 0.01). Surgeons placed the greatest value on Kidney quality, How difficult it is for the patient to be matched to a kidney (ie whether or not the patient is sensitized), and The age of the donor. This pilot study suggests a role for standardized education tools to help empower patients to be involved in this difficult decision. Development of decision aids can be guided by the results of this project

Heterogeneity in Schooling Rates of Return

This paper relaxes the assumption of homogeneous rates of return to schooling by employing nonparametric kernel regression. This approach allows us to examine the differences in rates of return to education both across and within groups. Similar to previous studies we find that on average blacks have higher returns to education than whites, natives have higher returns than immigrants and younger workers have higher returns than older workers. Contrary to previous studies we find that the average gap of the rate of return between white and black workers is larger than previously thought and the gap is smaller between immigrants and natives. We also uncover significant heterogeneity, the extent of which differs both across and within groups. The estimated densities of returns vary across groups and time periods and are often skewed. For example, during the period 1950-1990, at least 5% of whites have negative returns. Finally, we uncover the characteristics common amongst those with the smallest and largest returns to education. For example, we find that immigrants, aged 50-59, are most likely to have rates of return in the bottom 5% of the population.nonparametric, Mincer regressions, rate of return to education