Learn More
We study the dynamics and stability of legged locomotion in the horizontal plane. Motivated by experimental studies of insects, we develop two- and three-degree-of freedom rigid body models with pairs of 'virtual' elastic legs in intermittent contact with the ground. We focus on conservative compliant-legged models, but we also consider prescribed forces,(More)
We study the dynamics and stability of legged locomotion in the horizontal plane. We discuss the relevance of idealized mechanical models, developed in a companion paper, to recent experiments and simulations on insect running and turning. Applying our results to rapidly running cockroaches, we show that the models' gait and force characteristics match(More)
We extend the analysis of simple, energy-conserving models for the dynamics of insect locomotion in the horizontal plane developed in Schmitt and Holmes (2000a,b, 2001), where gaits characteristic of steady cockroach running and turning were evoked. In this paper, we include dissipation and energy inputs via active "muscles" in three forms: via prescribed(More)
helpful comments; and Chris Doucouliagos and Tom Stanley for kindly supplying the data for Figure 1. Executive Summary The employment effect of the minimum wage is one of the most studied topics in all of economics. This report examines the most recent wave of this research – roughly since 2000 – to determine the best current estimates of the impact of(More)
Animals can swerve, dodge, dive, climb, turn and stop abruptly. Their stability and maneuverability are remarkable, but a challenge to quantify. Formal stability analysis can allow for quantitative comparisons within and among species. Stability analysis used in concert with a template (a simple, general model that serves as a guide for control) can lead to(More)
It is widely believed that regional labor markets in the USA are highly flexible, so that employment shocks have only transitory effects on joblessness since induced migration quickly offsets much of the initial impact. However, time-series analysis of the response to shocks is very sensitive to errors of measurement, and such errors are large in some(More)
Acknowledgements We thank Heather Boushey and Dean Baker for many helpful comments and Nichole Szembrot for research assistance. Executive Summary This report reviews the national policies of 21 high-income economies, as of June 2008. We focus on two key aspects of parental leave policies: the level of support provided to parents; and the degree to which(More)
Executive Summary We use Bureau of Justice Statistics data to estimate that, in 2008, the United States had between 12 and 14 million ex-offenders of working age. Because a prison record or felony conviction greatly lowers ex-offenders' prospects in the labor market, we estimate that this large population lowered the total male employment rate that year by(More)