16,913 research outputs found
Does Housing Wealth Make Us Less Equal? The Role of Durable Goods in the Distribution of Wealth
We study the role an illiquid durable consumption good plays in determining the level of precautionary savings and the distribution of wealth in a standard Aiyagari model (i.e. a model with heterogeneous agents, idiosyncratic uncertainty, and borrowing constraints). Transactions costs induce an inaction region over which the durable stock and the associated user cost are not adjusted in response to changes in income, increasing, on average, the volatility of non-durable consumption. The volatility of total consumption is then a function of the share of the durable good in the utility function and the width of the inaction region. We are particularly interested in parameterizations which increase the precautionary motive for saving through an increase in "committed expenditure risk". We find, for an empirically relevant share of durable consumption and for all transaction costs below an upper threshold, that the level of precautionary savings is increasing in the transaction costs. Transaction costs have only a modest impact on the degree of wealth dispersion, as measured by the Gini index, as the associated increase in savings is close to linear in wealth. While we are unable to match the dispersion of wealth in the data, we increase the dispersion over a single asset model (Gini index of .71 for financial assets and .37 for total wealth) and we are able to match the relative dispersion of financial to durable assets, i.e. we find financial assets much more unequal than durable assets. We also match the ratio of housing wealth to total wealth for the median agent. We calibrate the model to data from the PSID, the CES, and the SCFPrecautionary Savings, Wealth Distribution, Durable Goods
Investigation into Wheelchair Mobility Control that Uses a Minimally Invasive Intra-Oral Palate Control Device utilising Resistopalatography Techniques
Interfacing with conventional wheelchair input devices is a major challenge when it comes to patients with high levels of disability. This paper intends to report on the new method of wheelchair mobility interfacing using Resistopalatog- raphy. The technique proposed here is based around utilising the tongue as the controlling muscle group to input desired movement into a force sensitive sensing dental retainer. Using the position of the force, and force applied a direction and speed metric can be calculated emulating conventional joystick output data. The resistopalatography technique has been applied to other Human Machine Interfacing areas with success [1]
The demand for homeowners insurance with bundled catastrophe coverages : Wharton project on managing catastrophic risks
In this paper, we estimate the demand for homeowner insurance in Florida. Since we are interested in a number of factors influencing demand, we approach the problem from two directions. We first estimate two hedonic equations representing the premium per contract and the price mark-up. We analyze how the contracts are bundled and how contract provisions, insurer characteristics and insured risk characteristics and demographics influence the premium per contract and the price mark-up. Second, we estimate the demand for homeowners insurance using two-stage least squares regression. We employ ISO's indicated loss costs as our proxy for real insurance services demanded. We assume that the demand for coverage is essentially a joint demand and thus we can estimate the demand for catastrophe coverage separately from the demand for noncatastrophe coverage. We determine that price elasticities are less elastic for catastrophic coverage than for non-catastrophic coverage. Further estimated income elasticities suggest that homeowners insurance is an inferior good. Finally, we conclude based on the results of a selection model that our sample of ISO reporting companies well represents the demand for insurance in the Florida market as a whole
Partial orders on partial isometries
This paper studies three natural pre-orders of increasing generality on the
set of all completely non-unitary partial isometries with equal defect indices.
We show that the problem of determining when one partial isometry is less than
another with respect to these pre-orders is equivalent to the existence of a
bounded (or isometric) multiplier between two natural reproducing kernel
Hilbert spaces of analytic functions. For large classes of partial isometries
these spaces can be realized as the well-known model subspaces and
deBranges-Rovnyak spaces. This characterization is applied to investigate
properties of these pre-orders and the equivalence classes they generate.Comment: 30 pages. To appear in Journal of Operator Theor
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