Consumption inequality and partial insurance

This paper examines the transmission of income inequality into consumption inequality and in so doing investigates the degree of insurance to income shocks. Panel data on income from the PSID is combined with consumption data from repeated CEX cross-sections to identify the degree of insurance to permanent and transitory shocks. In the process we also present new evidence of the growth in the variance of permanent and transitory shocks in the US during the 1980s. We find some partial insurance of permanent income shocks with more insurance possibilities for the college educated and those nearing retirement. We find little evidence against full insurance for transitory income shocks except among low income households. Tax and welfare benefits are found to play an important role in insuring permanent shocks. Adding durable expenditures to the consumption measure suggests that durable replacement is an important insurance mechanism, especially for transitory income shocks

Consumption inequality and partial insurance

This paper uses panel data on household consumption and income to evaluate the degree of insurance to income shocks. Our aim is to describe the transmission of income inequality into consumption inequality by contrasting shifts in the cross-sectional distribution of income growth with shifts in the cross-sectional distribution of consumption growth. We combine panel data on income from the PSID with consumption data from repeated CEX cross-sections. The results point to some partial insurance but reject the complete market restrictions. We find a greater degree of insurance for transitory shocks and differences in the degree of insurance over time and across demographic groups. We also document the importance of durables and of taxes and transfers as a means of insurance

Imputing consumption in the PSID using food demand estimates from the CEX

In this paper we discuss an empirical strategy that allows researchers to impute consumptiondata from the CEX to the PSID. The strategy consists of inverting a demand for food equationestimated in the CEX. We discuss the conditions under which such procedure is successful inreplicating the trends of the first two moments of the consumption distribution. We argue thattwo factors appear to be empirically relevant: accounting for differences in the distribution offood expenditures in the two data sets, and accounting for the presence of measurement error inconsumption data in the CEX. In this paper we discuss an empirical strategy that allows researchers to impute consumptiondata from the CEX to the PSID. The strategy consists of inverting a demand for food equationestimated in the CEX. We discuss the conditions under which such procedure is successful inreplicating the trends of the first two moments of the consumption distribution. We argue thattwo factors appear to be empirically relevant: accounting for differences in the distribution offood expenditures in the two data sets, and accounting for the presence of measurement error inconsumption data in the CEX

Partial insurance, information,and consumption dynamics

This paper uses panel data on household consumption and income to evaluate the degree ofinsurance to income shocks. Our aim is to describe the transmission of income inequality intoconsumption inequality. Our framework nests the special cases of self-insurance and the completemarkets assumption. We assess the degree of insurance over and above self-insurance throughsavings by contrasting shifts in the cross-sectional distribution of income growth with shifts in thecross-sectional distribution of consumption growth, and analyzing the way these two measures ofhousehold welfare correlate over time. We combine panel data on income from the PSID withconsumption data from repeated CEX cross-sections in a structural way, i.e. using conventionaldemand analysis rather than reduced form imputation procedures. Our results point to some partialinsurance but reject the complete markets restriction. We find a greater degree of insurance fortransitory shocks and differences in the degree of insurance over time and across education. Wealso document the importance of durables and of taxes and transfers as a means of insurance. This paper uses panel data on household consumption and income to evaluate the degree ofinsurance to income shocks. Our aim is to describe the transmission of income inequality intoconsumption inequality. Our framework nests the special cases of self-insurance and the completemarkets assumption. We assess the degree of insurance over and above self-insurance throughsavings by contrasting shifts in the cross-sectional distribution of income growth with shifts in thecross-sectional distribution of consumption growth, and analyzing the way these two measures ofhousehold welfare correlate over time. We combine panel data on income from the PSID withconsumption data from repeated CEX cross-sections in a structural way, i.e. using conventionaldemand analysis rather than reduced form imputation procedures. Our results point to some partialinsurance but reject the complete markets restriction. We find a greater degree of insurance fortransitory shocks and differences in the degree of insurance over time and across education. Wealso document the importance of durables and of taxes and transfers as a means of insurance

Effect of Nutrition on the Carcass Composition and Quality of Cattle

Beef is a highly desirable food, both nutritionally and for the pleasure it gives during its consumption. Protein of high quality is the major nutritional asset of beef, as well as supplying certain minerals and vitamins. As important as this role is, it is not the main reason that beef is the most desired of all meats. Beef is consumed because it provides great satisfaction. What then contributes of this satisfaction

Light-cone coordinates based at a geodesic world line

Continuing work initiated in an earlier publication [Phys. Rev. D 69, 084007 (2004)], we construct a system of light-cone coordinates based at a geodesic world line of an arbitrary curved spacetime. The construction involves (i) an advanced-time or a retarded-time coordinate that labels past or future light cones centered on the world line, (ii) a radial coordinate that is an affine parameter on the null generators of these light cones, and (iii) angular coordinates that are constant on each generator. The spacetime metric is calculated in the light-cone coordinates, and it is expressed as an expansion in powers of the radial coordinate in terms of the irreducible components of the Riemann tensor evaluated on the world line. The formalism is illustrated in two simple applications, the first involving a comoving world line of a spatially-flat cosmology, the other featuring an observer placed on the axis of symmetry of Melvin's magnetic universe.Comment: 11 pages, 1 figur

The hippocampus and inferential reasoning: building memories to navigate future decisions

A critical aspect of inferential reasoning is the ability to form relationships between items or events that were not experienced together. This review considers different perspectives on the role of the hippocampus in successful inferential reasoning during both memory encoding and retrieval. Intuitively, inference can be thought of as a logical process by which elements of individual existing memories are retrieved and recombined to answer novel questions. Such flexible retrieval is sub-served by the hippocampus and is thought to require specialized hippocampal encoding mechanisms that discretely code events such that event elements are individually accessible from memory. In addition to retrieval-based inference, recent research has also focused on hippocampal processes that support the combination of information acquired across multiple experiences during encoding. This mechanism suggests that by recalling past events during new experiences, connections can be created between newly formed and existing memories. Such hippocampally mediated memory integration would thus underlie the formation of networks of related memories that extend beyond direct experience to anticipate future judgments about the relationships between items and events. We also discuss integrative encoding in the context of emerging evidence linking the hippocampus to the formation of schemas as well as prospective theories of hippocampal function that suggest memories are actively constructed to anticipate future decisions and actions

The Stac Fada “impact ejecta” layer: not what it seems

The Stac Fada Member (SFM) forms part of the Stoer Group of the Torridonian of NW Scotland. The SFM is unique in the Torridonian, being characterized by the presence of greenish altered glass clasts. Its origin has been debated for decades with several hypotheses being proposed but all invoking some connection with volcanic activity in the region. More recently, Amor et al. suggested that the SFM represents “a chord section through the continuous ejecta blanket surrounding an impact crater”. Here, we confirm the presence of shocked material within the SFM and then discuss its origin

The energy partitioning of non-thermal particles in a plasma: or the Coulomb logarithm revisited

The charged particle stopping power in a highly ionized and weakly to moderately coupled plasma has been calculated to leading and next-to-leading order by Brown, Preston, and Singleton (BPS). After reviewing the main ideas behind this calculation, we use a Fokker-Planck equation derived by BPS to compute the electron-ion energy partitioning of a charged particle traversing a plasma. The motivation for this application is ignition for inertial confinement fusion -- more energy delivered to the ions means a better chance of ignition, and conversely. It is therefore important to calculate the fractional energy loss to electrons and ions as accurately as possible, as this could have implications for the Laser Megajoule (LMJ) facility in France and the National Ignition Facility (NIF) in the United States. The traditional method by which one calculates the electron-ion energy splitting of a charged particle traversing a plasma involves integrating the stopping power dE/dx. However, as the charged particle slows down and becomes thermalized into the background plasma, this method of calculating the electron-ion energy splitting breaks down. As a result, the method suffers a systematic error of order T/E0, where T is the plasma temperature and E0 is the initial energy of the charged particle. In the case of DT fusion, for example, this can lead to uncertainties as high as 10% or so. The formalism presented here is designed to account for the thermalization process, and in contrast, it provides results that are near-exact.Comment: 10 pages, 3 figures, invited talk at the 35th European Physical Society meeting on plasma physic