A note on GMM-estimation of probit models with endogenous regressors

Dagenais (1999) and Lucchetti (2002) have demonstrated that the naive GMM estimator of Grogger (1990) for the probit model with an endogenous regressor is not consistent. This paper completes their discussion by explaining the reason for the inconsistency and presenting a natural solution. Furthermore, the resulting GMM estimator is analyzed in a Monte-Carlo simulation and compared with alternative estimators.generalized method of moments, probit model, endogenous regressor

Criminals and risk attitude

We show that whatever the representation of criminals' preferences under risk, the assumption according to which they are strongly risk averse individuals is not consistent with the available observations establishing that criminals are more sensitive to shifts in the probability of sanction than to changes in the level of the sanction. We suggest that: 1/ while a weakening of the risk aversion assumption may be useful, the risk seeking assumption may be better suited for criminals; 2/ the relevant assumption regarding criminals' risk attitude may depend on the policy instruments that models of crime deterrence take into account; 3/ additional experiments, including both monetary penalties and non monetary sanctions would be useful in order to learn more about their sensibility to probability, monetary and non monetary sanctions.Risk aversion; monetary and non monetary sanctions; State Dependent preferences and RDEU models

Comparison of EFTEM and STEM EELS plasmon imaging of gold nanoparticles in a monochromated TEM

We present and compare two different imaging techniques for plasmonic excitations in metallic nanoparticles based on high energy-resolution electron energy-loss spectroscopy in a monochromated transmission electron microscope. We demonstrate that a recently developed monochromated energy-filtering (EFTEM) approach can be used in addition to the well established scanning technique to directly obtain plasmon images in the energy range below 1 eV. The EFTEM technique is described in detail, and a double experiment performed on the same, triangular gold nanoparticle compares equivalent data acquired by both techniques, respectively

Are Welfare Eligible Households Forward Looking?

A consensus has formed in the welfare reform literature suggesting that welfare eligible households (WEH) “bank†benefits in the presence of time limits, either by delaying enrollment in welfare or exiting well before the time limit is reached. In this study, we use the standard labor-leisure lifetime utility to analyze the behavioral effects of imposing time limits on welfare use. Our approach is different from our predecessors (which model welfare participation) in that we model delayed enrollment in and early exit from welfare. Our results suggest that prior to time limits, WEH enroll in welfare as soon as eligibility is established and remain on assistance programs until their youngest children reach adulthood. Moreover, time limits do not alter this behavior in WEH with older children. As such, being “forward looking†in an era of time limits is not a sufficient condition for banking welfare benefits.

Welfare Transitions in the 1990s: The Economy, Welfare Policy, and the EITC

The rapid decline in the welfare caseload remains a subject of keen interest to both policymakers and researchers. In this paper, I use data from the Survey of Income and Program Participation spanning the period from 1986 to 1999 to analyze how the economy, welfare reform, the Earned Income Tax Credit, and other factors influenced welfare entries and exits, which in turn affect the caseload. I find that the decline in the welfare caseload resulted from both increases in exits and decreases in entries. Entries were most significantly affected by the economy, the decline in the real value of welfare benefits, and the expansion of the EITC. The EITC had substantial effects on initial entries onto welfare. Exits were most significantly affected by the economy and federal welfare reform. Federal reform had its greatest effects on longer-term spells of the type generally experienced by more disadvantaged recipients. Some out-of-sample predictions help explain the otherwise puzzling observation that, despite substantial increases in the unemployment rate since 2000, caseloads have remained roughly constant.

Welfare Reform, Work and Wages: A Summary of the US Experience

Workfare, Wohlfahrtstheorie, Arbeit, Lohn, Vereinigte Staaten, Welfare economics, Labour, Wages, United States

High-resolution surface plasmon imaging of gold nanoparticles by energy-filtered transmission electron microscopy

We demonstrate the imaging capabilities of energy-filtered transmission electron microscopy at high-energy resolution in the low-energy-loss region, reporting the direct image of a surface plasmon of an elongated gold nanoparticle at energies around 1 eV. Using complimentary model calculations performed within the boundary element method approach we can assign the observed results to the plasmon eigenmodes of the metallic nanoparticle

Identifying the Effect of a Welfare-to-Work Program Using Capacity Constraint: a New York City Quasi-Experinmet

In 1999 general assistance recipients in New York City were required to participate in a job training and outplacement assistance program. Initially, recipients were enrolled in ‘waves’ due to capacity constraints. The program’s impact is identified using a quasiexperiment in which selectees are compared to concomitantly eligible non-selectees. Selectees are 15 percentage points more likely to start a job and 10 percentage points more likely to exit welfare than are non-selectees. This methodology is important since random-assignment experiments can be costly and difficult to implement. Further, experiments are not impervious to criticism; this procedure addresses three of five known shortcomings

A preliminary investigation of welfare migration induced by time limits

Studies on welfare programs in the United States have identified three types of welfare migration (employment, benefit, and amenity-related). This paper introduces a fourth type of migration induced by welfare time limits. After a welfare-dependent family runs out of benefits, it is possible for them to reset the Temporary Assistance for Needy Families time clock by crossing state lines to extend their benefits. Our theoretical results suggest that the likelihood of migration increases if the migration distance is small or the gain from the move is large. We hypothesize that, ceteris paribus, families migrating in order to extend their benefits will minimize the distance they migrate, and will be likely to move into the nearest state, especially into counties just across the state border. We utilize macro data at the county level to look for evidence of time-limit induced migration. Estimates indicate that time limits may be associated with an increase in welfare migration.welfare reform; migration

Markov Forecasting Methods for Welfare Caseloads

Forecasting welfare caseloads, particularly turning points, has become more important than ever. Since welfare reform, welfare has been funded via a block grant, which means that unforeseen changes in caseloads can have important fiscal implications for states. In this paper I develop forecasts based on the theory of Markov chains. Since today's caseload is a function of the past caseload, the caseload exhibits inertia. The method exploits that inertia, basing forecasts of the future caseload on past functions of entry and exit rates. In an application to California welfare data, the method accurately predicted the late-2003 turning point roughly one year in advance.