Comparing patterns of default among prime and subprime mortgages

This article compares default patterns among prime and subprime mortgages, analyzes the factors correlated with default, and examines how forecasts of defaults are affected by alternative assumptions about trends in home prices. The authors find that extremely pessimistic forecasts of home price appreciation could have generated predictions of subprime defaults that were closer to the actual default experience for loans originated in 2006 and 2007. However, for prime loans one would have also had to anticipate that defaults would become much more sensitive to home prices.

Enhancing financial stability: the case of financial market utilities

The sweeping overhaul of the nation’s financial regulatory system that was signed into law on July 21, 2010, will touch virtually every aspect of financial markets. This Chicago Fed Letter focuses on provisions in the Dodd–Frank Wall Street Reform and Consumer Protection Act that affect “financial market utilities,” critical behind-the-scenes institutions and arrangements that ensure the smooth functioning of financial markets.Financial crises ; Financial markets

USSR Space Life Sciences Digest, volume 1, no. 4

An overview of the developments and direction of the USSR Space Life Sciences Program is given. Highlights of launches, program development, and mission planning are given. Results of ground-based research and space flight studies are summarized. Topics covered include: space medicine and physiology; space biology, and life sciences and technology

Strategies for success in financial education

The Federal Reserve Bank of Chicago will host a conference, Financial Literacy, Financial Education, and the Federal Reserve: Strategies for Success, on September 11, 2009. This article reviews some of the financial education activities throughout the Federal Reserve System.Financial literacy

Premise Selection and External Provers for HOL4

Learning-assisted automated reasoning has recently gained popularity among the users of Isabelle/HOL, HOL Light, and Mizar. In this paper, we present an add-on to the HOL4 proof assistant and an adaptation of the HOLyHammer system that provides machine learning-based premise selection and automated reasoning also for HOL4. We efficiently record the HOL4 dependencies and extract features from the theorem statements, which form a basis for premise selection. HOLyHammer transforms the HOL4 statements in the various TPTP-ATP proof formats, which are then processed by the ATPs. We discuss the different evaluation settings: ATPs, accessible lemmas, and premise numbers. We measure the performance of HOLyHammer on the HOL4 standard library. The results are combined accordingly and compared with the HOL Light experiments, showing a comparably high quality of predictions. The system directly benefits HOL4 users by automatically finding proofs dependencies that can be reconstructed by Metis

Effects of deflected thrust on the longitudinal aerodynamic characteristics of a close-coupled wing-canard configuration

The effects of power on the longitudinal aerodynamic characteristics of a close-coupled wing-canard fighter configuration with partial-span rectangular nozzles at the trailing edge of the wing were investigated. Data were obtained on a basic wing-strake configuration for nozzle and flap deflections from 0 deg to 30 deg and for nominal thrust coefficients from 0 to 0.30. The model was tested over an angle-of-attack range from -2 deg to 40 deg at Mach numbers of 0.15 and 0.18. Results show substantial improvements in lift-curve slope, in maximum lift, and in drag-due-to-lift efficiency when the canard and strakes have been added to the basic wing-fuselage (wing-alone) configuration. Addition of power increased both lift-curve slope and maximum lift, improved longitudinal stability, and reduced drag due to lift on both the wing-canard and wing-canard-strake configurations. These beneficial effects are primarily derived from boundary-layer control due to moderate thrust coefficients which delay flow separation on the nozzle and inboard portion of the wing flaps

Summary of low-speed longitudinal aerodynamics of two powered close-coupled wing-canard fighter configurations

Investigations of the low speed longitudinal characteristics of two powered close coupled wing-canard fighter configurations are discussed. Data obtained at angles of attack from -2 deg to 42 deg, Mach numbers from 0.12 to 0.20, nozzle and flap deflections from 0 deg to 40 deg, and thrust coefficients from 0 to 2.0, to represent both high angle of attack subsonic maneuvering characteristics and conventional takeoff and landing characteristics are examined. Data obtained with the nozzles deflected either 60 deg or 90 deg and the flaps deflected 60 deg to represent vertical or short takeoff and landing characteristics are discussed

How do benefit adjustments for government transfer programs compare with their participants' inflation experiences?

The authors measure the inflation experienced by demographic groups that likely received benefits from major government transfer programs during the period 1980–2010. They then compare the group-specific inflation measures with the transfer programs’ benefit adjustments, which are typically based on aggregate inflation. The extent to which the program benefits keep up with group inflation differs across the programs and their targeted groups, depending on both the ways in which the benefits are adjusted for price changes and the spending patterns of the various groups.Inflation (Finance) - United States ; Public welfare

Wind tunnel test results of a new leading edge flap design for highly swept wings, a vortex flap

A leading edge flap design for highly swept wings, called a vortex flap, was tested on an arrow wing model in a low speed wind tunnel. A vortex flap differs from a conventional plain flap in that it has a leading edge tab which is counterdeflected from the main portion of the flap. This results in intentional separation at the flap leading edge, causing a vortex to form and lie on the flap. By trapping this vortex, the vortex flap can result in significantly improved wing flow characteristics relative to conventional flaps at moderate to high angles of attack, as demonstrated by the flow visualization results of this tests