A Dynamic Look at Subprime Loan Performance

Does delinquency have any predictive power for the future performance of a mortgage? Analysis of a sample of subprime mortgages from the Loanperformance database on securitized private-label pool collateral using a two-step estimation procedure to control for the endogeneity of delinquency reveals strong support for the distressed prepayment theory that very delinquent loans are more likely to prepay than to default and that prepayment rates increase substantially as delinquency intensity increases. While delinquency leads predominantly to termination of a loan through prepayment, negative equity leads to termination through default. Does delinquency have any predictive power for the future performance of a mortgage? Analysis of a sample of subprime mortgages from the Loanperformance database on securitized private-label pool collateral using a two-step estimation procedure to control for the endogeneity of delinquency reveals strong support for the distressed prepayment theory that very delinquent loans are more likely to prepay than to default and that prepayment rates increase substantially as delinquency intensity increases. While delinquency leads predominantly to termination of a loan through prepayment, negative equity leads to termination through default

The impact of new signals on precise marine navigation - initial results from an experiment in Harwich Harbour

The General Lighthouse Authorities of the United Kingdom and Ireland (GLAs) are supporting a project at University College London (UCL) to study whether it is possible to meet the International Maritime Organisation’s (IMO) future requirements for port and harbour approach using future GNSS constellations, as detailed in IMO resolution A.915. This paper presents the results of a trial focusing on the accuracy, integrity, availability and continuity of port navigation, port approach, and docking. Abstract The required accuracy for docking is 0.1 m (95\%), which currently necessitates the use of Real Time Kinematic (RTK) processing. We consider the single-epoch geometry-based approach, which is robust against loss of lock and will fully benefit from the additional satellites. The trial was held at the beginning of May 2008 and saw THV Alert navigate into Harwich Harbour while satellite observation data were recorded from the vessel and from shore-based reference stations. Additional data were obtained from nearby Ordnance Survey reference stations, and two total stations were used to track the vessel’s passage to provide a truth model. Several modernised GPS satellites were tracked. The data were processed under different scenarios, using software developed at UCL, and the positioning performance analysed. Abstract Providing integrity for single-epoch RTK is particularly difficult. The identification of phase observation outliers is not possible before the integer ambiguities are resolved, but an undetected outlier could prevent successful ambiguity resolution. However, it will not always be necessary to fix every ambiguity to achieve the required precision, particularly with a multi-GNSS constellation. This paper introduces a new algorithm for partial ambiguity resolution in the presence of measurement bias that has been developed and tested at UCL.  This algorithm results in an improved ambiguity resolution success rate at the expense of computation time

The Delinquency of Subprime Mortgages

The lag between the time that a borrower stops making payments on a mortgage and the termination of the loan plays a critical role in the costs borne by both borrower and lender on defaulted loans. While the prior literature uses a multinomial logit approach, statistical tests indicate that we cannot accept the associated assumption of Independence of Irrelevant Alternatives (IIA). Using a nested logit specification our results suggest that the recipe for delinquency involves young loans to low credit score borrowers with low or no documentation in housing markets with moderately volatile and flat or declining nominal house prices

Amplitude-equation formalism for four-wave-mixing geometry with transmission gratings

An amplitude equation is derived for a four-wave-mixing geometry with nearly counterpropagating, mutually incoherent, nondiffracting pump beams, spatially overlapping in a photorefractive material with a nonlocal response. This equation extends the earlier linear two-dimensional theory to the weakly nonlinear regime. The analysis also starts from a more complete equation for the photorefractive effect, which leads to the prediction of novel effects especially apparent in the nonlinear regime. Precise predictions for the spatiotemporal behavior of the grating amplitude in the nonlinear regime are presented. The range of validity of the amplitude equation is studied. The characteristics of the instability in the nonlinear regime are analyzed through a front-selection analysis

A vapor barrier for cold testing printed circuit cards

Cold testing method prevents formation of frost on printed circuit boards and part holders during testing at sub-zero temperatures. Freon permits rapid attainment of the required testing temperature

A dynamic look at subprime loan performance

This paper examines the implications of delinquency on the performance of subprime mortgages. Specifically, we examine whether delinquency has any predictive power of the future performance of a mortgage. Using a sample of subprime mortgages from the Loan performance database on securitized private-label pool collateral, we utilize a two-step estimation procedure to control for the endogeneity of delinquency in an estimation of default and prepayment probabilities. We find strong support for the *distressed prepayment* theory that very delinquent loans are more likely to prepay than to default and that the rate of increase of prepayment is substantially larger as delinquency intensity increases. Delinquency predominately leads to termination of a loan through prepayment while negative equity leads to termination through default.Mortgages

Dual pathway spindle assembly increases both the speed and the fidelity of mitosis

Roughly half of all animal somatic cell spindles assemble by the classical prophase pathway, in which the centrosomes separate ahead of nuclear envelope breakdown (NEBD). The remainder assemble by the prometaphase pathway, in which the centrosomes separate following NEBD. Why cells use dual pathway spindle assembly is unclear. Here, by examining the timing of NEBD relative to the onset of Eg5-mEGFP loading to centrosomes, we show that a time window of 9.2 ± 2.9 min is available for Eg5-driven prophase centrosome separation ahead of NEBD, and that those cells that succeed in separating their centrosomes within this window subsequently show .3-fold fewer chromosome segregation errors and a somewhat faster mitosis. A longer time window would allow more cells to complete prophase centrosome separation and further reduce segregation errors, but at the expense of a slower mitosis. Our data reveal dual pathway mitosis in a new light, as a substantive strategy that increases both the speed and the fidelity of mitosis

An assessment of apple varieties for their suitability in organic production systems

Twenty seven varieties of apple were assessed for their susceptibility to apple scab, mildew and rosy apple aphid in a replicated experiment at East Malling Research. The varieties most affected by mildew were Goldrush, DL11, Liberty, Bohemia and Pinova. Ceeval, Discovery, Edward VII, Howgate Wonder, Rajka, Rebella and Topaz had the lowest incidences of mildew. The highest incidence of scab occurred on Pilot and Pinova, but infestation was low throughout the assessment period. In 2006 when aphid populations were high, Liberty, Goldrush and Delorina had no aphid infestations, and low infestations were seen on Edward VII, Resi and Santana