Child labor, income shocks, and access to credit

Although a growing theoretical literature points to credit constraints asan important source of inefficiently high child labor, little work has been done to assess its empirical relevance. Using panel data from Tanzania, the authors find that households respond to transitory income shocks by increasing child labor, but that the extent to which child labor is used as a buffer is lower when households have access to credit. These findings contribute to the empirical literature on the permanent income hypothesis by showing that credit-constrained households actively use child labor to smooth their income. Moreover, they highlight a potentially important determinant of child labor and, as a result, a mechanism that can be used to tackle it.Environmental Economics&Policies,Labor Policies,Children and Youth,Economic Theory&Research,Health Economics&Finance,Health Economics&Finance,Street Children,Environmental Economics&Policies,Youth and Governance,Children and Youth

The consequences of child labor : evidence from longitudinal data in rural Tanzania

This paper exploits a unique longitudinal data set from Tanzania to examine the consequences of child labor on education, employment choices, and marital status over a 10-year horizon. Shocks to crop production and rainfall are used as instrumental variables for child labor. For boys, the findings show that a one-standard-deviation (5.7 hour) increase in child labor leads 10 years later to a loss of approximately one year of schooling and to a substantial increase in the likelihood of farming and of marrying at a younger age. Strikingly, there are no significant effects on education for girls, but there is a significant increase in the likelihood of marrying young. The findings also show that crop shocks lead to an increase in agricultural work for boys and instead lead to an increase in chore hours for girls. The results are consistent with education being a lower priority for girls and/or with chores causing less disruption for education than agricultural work. The increased chore hours could also account for the results on marriage for girls.Street Children,Youth and Governance,Labor Policies,Labor Markets,Children and Youth

The 32-GHz performance of the DSS-14 70-meter antenna: 1989 configuration

The results of preliminary 32 GHz calibrations of the 70 meter antenna at Goldstone are presented. Measurements were done between March and July 1989 using Virgo A and Venus as the primary efficiency calibrators. The flux densites of theses radio sources at 32 GHz are not known with high accuracy, but were extrapolated from calibrated data at lower frequencies. The measured value of efficiency (0.35) agreed closely with the predicted value (0.32), and the results are very repeatable. Flux densities of secondary sources used in the observations were subsequently derived. These measurements were performed using a beamswitching radiometer that employed an uncooled high-electron mobility transistor (HEMT) low-noise amplifier. This system was installed primarily to determine the performance of the antenna in its 1989 configuration, but the experience will also aid in successful future calibration of the Deep Space Network (DSN) at this frequency

Normalized ghost imaging

We present an experimental comparison between different iterative ghost imaging algorithms. Our experimental setup utilizes a spatial light modulator for generating known random light fields to illuminate a partially-transmissive object. We adapt the weighting factor used in the traditional ghost imaging algorithm to account for changes in the efficiency of the generated light field. We show that our normalized weighting algorithm can match the performance of differential ghost imaging

Quantum Teleportation of Light

Requirements for the successful teleportation of a beam of light, including its temporal correlations, are discussed. Explicit expressions for the degrees of first- and second-order optical coherence are derived. Teleportation of an antibunched photon stream illustrates our results.Comment: 4 pages, 5 figure

Child labor: The role of income variability and access to credit across countries

This paper examines the relationship between child labor and access to credit at a cross-country level. Even though this link is theoretically central to child labor, so far there has been little work done to assess its importance empirically. We measure child labor as a country aggregate, and credit constraints are proxied by the extent of financial development. These two variables display a strong negative relationship, which we show is robust to selection on observables (by controlling for a wide range of variables such as GDP per capita, urbanization, initial child labor, schooling, fertility, legal institutions, inequality, and openness, and by allowing for a nonparametric functional form), and to selection on unobservables (by allowing for fixed effects). We find that the magnitude of the association between our proxy of access to credit and child labor is large in the subsample of poor countries. Moreover, in the absence of developed financial markets, households appear to resort substantially to child labor in order to cope with income variability. This evidence suggests that policies aimed at widening households' access to credit could be effective in reducing the extent of child labor

Do households resort to child labor to cope with income shocks?

Using four rounds of panel household data from the Kagera region of Tanzania, we show that transitory income shocks - measured by the value of crop lost by farming households - lead to significantly increased child labor. A one standard deviation increase in the shock is associated with a 10% increase in mean child working hours. Moreover, we find that households with collateralizable assets - which we interpret as a proxy for access to credit - are better able to offset the effects of income shocks. This evidence supports the view that credit market imperfections are an important determinant of child labor

Investigation of the preparation of materials in space. Task 4 - Field management for weightless containerless processing Quarterly progress report, 22 Aug. - 31 Oct. 1969

Weightless containerless processing for space, electromagnetic position control, force measurements and techniques, and hydrodynamic

From drag-reducing riblets to drag-increasing ridges

Small drag-reducing riblets and larger drag-increasing ridges are longitudinally invariant and laterally periodic surface structures that differ only in the details of their lateral periodicity and their size in viscous units. Due to their different drag behaviour, typically riblets and ridges have been analysed separately. By studying experimentally trapezoidal-grooved surfaces of different sizes, we address systematically the transition from riblet-like to ridge-like behaviour in a unified framework. The structure height and lateral wavelength are varied both physically, by considering eight different surfaces, and in their viscous-scaled form, by spanning a wide range of bulk Reynolds number $Re_b$. The effective skin-friction coefficient $C_f$ is determined via pressure-drop measurement in a turbulent channel flow facility designed for accurate drag measurements. An unexpectedly rich drag behaviour is unveiled, in which different drag regimes are distinguished depending on the value of $l^+_g$, the viscous-scaled square root of the groove area. The well-known drag-reducing regime of riblets that spans up to $l^+_g=17$ is followed by a regime in which the roughness function $\Delta U^+$ increases logarithmically with $l^+_g$, indicating an apparent fully rough behaviour up to $l^+_g≈40$. Further increase of $l^+_g$ leads to a clear departure from the fully rough regime, and an unexpected non-monotonic behaviour of the roughness function $\Delta U^+$ for $50<l^+_g<200$ is reported for the first time. For sufficiently large $Re_b$ and $l_g$, it is shown that a single parameter, similar to the classical hydraulic diameter, is sufficient to describe the drag behaviour of ridges. We find that an appropriate definition of the effective channel height is crucial for interpreting the drag behaviour. When the longitudinal protrusion height of the structured surface is accounted for in the channel height definition, a laminar flow exhibits the same $C_f(Re_b)$ relation known for flat surfaces. This approach thus allows us to discern the modification of $C_f$ induced by turbulence. We provide predictive correlations for the fully rough regime and the high Reynolds number range of trapezoidal-grooved surfaces that become possible thanks to the chosen channel height definition

Polarization quantum properties in type-II Optical Parametric Oscillator below threshold

We study the far field spatial distribution of the quantum fluctuations in the transverse profile of the output light beam generated by a type II Optical Parametric Oscillator below threshold, including the effects of transverse walk-off. We study how quadrature field correlations depend on the polarization. We find spatial EPR entanglement in quadrature-polarization components: For the far field points not affected by walk-off there is almost complete noise suppression in the proper quadratures difference of any orthogonal polarization components. We show the entanglement of the state of symmetric intense, or macroscopic, spatial light modes. We also investigate nonclassical polarization properties in terms of the Stokes operators. We find perfect correlations in all Stokes parameters measured in opposite far field points in the direction orthogonal to the walk-off, while locally the field is unpolarized and we find no polarization squeezing.Comment: 16 pages, 18 figure