Negative equity does not reduce homeowners' mobility

Some commentators have argued that the housing crisis may harm labor markets because homeowners who owe more than their homes are worth are less likely to move to places that have productive job opportunities. I show that, in the available data, negative equity does not make homeowners less mobile. In fact, homeowners who have negative equity are slightly more likely to move than homeowners who have positive equity. Ferreira, Gyourko, and Tracy's (2010) contrasting result that negative equity reduces mobility arises because they systematically drop some negative-equity homeowners' moves from the data.> some negative-equity homeowners' moves from the data.

Heterogeneous Risk Preferences and the Welfare Cost of Business Cycles

I study the welfare cost of business cycles in a complete-markets economy where some people are more risk averse than others. Relatively more risk-averse people buy insurance against aggregate risk, and relatively less risk-averse people sell insurance. These trades reduce the welfare cost of business cycles for everyone. Indeed, the least risk-averse people benet from business cycles. Moreover, even innitely risk-averse people suer only nite and, in my empirical estimates, very small welfare losses. In other words, when there are complete insurance markets, aggregate uctuations in consumption are essentially irrelevant not just for the average person { the surprising nding of Lucas (1987) { but for everyone in the economy, no matter how risk averse they are. If business cycles matter, it is because they aect productivity or interact with uninsured idiosyncratic risk, not because aggregate risk per se reduces welfare.business cycles; risk aversion; risk sharing; heterogeneity

Phase plane displays detect incipient failure in servo system testing

Computer based data conditioning and display technique detects incipient failure in servo system testing, for use in prelaunch checkout of complex nonlinear servomechanisms. These phase plane displays enable identification of, on line, unusual or abnormal servo responses which can be displayed compactly in the time domain on a cathode ray tube

Shield weight optimization using Monte Carlo transport calculations

Outlines are given of the theory used in FASTER-3 Monte Carlo computer program for the transport of neutrons and gamma rays in complex geometries. The code has the additional capability of calculating the minimum weight layered unit shield configuration which will meet a specified dose rate constraint. It includes the treatment of geometric regions bounded by quadratic and quardric surfaces with multiple radiation sources which have a specified space, angle, and energy dependence. The program calculates, using importance sampling, the resulting number and energy fluxes at specified point, surface, and volume detectors. Results are presented for sample problems involving primary neutron and both primary and secondary photon transport in a spherical reactor shield configuration. These results include the optimization of the shield configuration

Interstate migration has fallen less than you think: consequences of hot deck imputation in the Current Population Survey

We show that the significant drop in the annual interstate migration rate between the 2005 and 2006 Current Population Surveys is a statistical artifact. The Census Bureau’s imputation procedure for dealing with missing data before the 2006 survey year inflated the estimated interstate migration rate. An undocumented change in the procedure corrected the problem for the 2006 and later surveys, thus reducing the estimated migration rate. The change in imputation procedures explains 90 percent of the reported decrease in interstate migration between 2005 and 2006, and 42 percent of the decrease between 2000 (the recent high-water mark) and 2010. After we remove the effect of the change in procedures, we find that the annual interstate migration rate follows a smooth downward trend from 1996 to 2010. The 2007–2009 recession is not associated with any additional decrease in interstate migration relative to trend.

Computer program uses Monte Carlo techniques for statistical system performance analysis

Computer program with Monte Carlo sampling techniques determines the effect of a component part of a unit upon the overall system performance. It utilizes the full statistics of the disturbances and misalignments of each component to provide unbiased results through simulated random sampling

The diminishing liquidity premium

Previous evidence suggests that less liquid stocks entail higher average returns. Using NYSE data, we present evidence that both the sensitivity of returns to liquidity and liquidity premia have significantly declined over the past four decades to levels that we cannot statistically distinguish from zero. Furthermore, the profitability of trading strategies based on buying illiquid stocks and selling illiquid stocks has declined over the past four decades, rendering such strategies virtually unprofitable. Our results are robust to several conventional liquidity measures related to volume. When using liquidity measure that is not related to volume, we find just weak evidence of a liquidity premium even in the early periods of our sample. The gradual introduction and proliferation of index funds and exchange traded funds is a possible explanation for these results

Interstate migration has fallen less than you think: consequences of hot deck imputation in the Current Population Survey

We show that much of the recent reported decrease in interstate migration is a statistical artifact. Before 2006, the Census Bureau’s imputation procedure for dealing with missing data in the Current Population Survey inflated the estimated interstate migration rate. An undocumented change in the procedure corrected the problem starting in 2006, thus reducing the estimated migration rate. The change in imputation procedures explains 90 percent of the reported decrease in interstate migration between 2005 and 2006, and 42 percent of the decrease between 2000 (the recent high-water mark) and 2010. After we remove the effect of the change in procedures, we find that the annual interstate migration rate follows a smooth downward trend from 1996 to 2010. Contrary to popular belief, the 2007–2009 recession is not associated with any additional decrease in interstate migration relative to trend.