The Earned Income Tax Credit and the Labor Supply of Married Couples

Over 18 million taxpayers are projected to receive the Earned Income Tax Credit (EITC) in tax year 1997, at a total cost to the federal government of about 25 billion dollars. The EITC is refundable, so any amount of the credit exceeding the family’s tax liability is returned in the form of a cash refund. Advocates of the credit argue that this redistribution occurs with much less distortion to labor supply than that caused by other elements of the welfare system. This popular view that the credit “encourages work effort” is unlikely to hold among married couples. Theory suggests that primary earners (typically men) would increase labor force participation, but secondary earners would reduce their labor supply in response to an EITC. We study the labor supply response of married couples to several EITC expansions between 1984 and 1996. Although our primary interest is the response to changes in the budget set induced by the EITC, our estimation strategy takes account of budget set changes caused by federal tax policy, and by cross-sectional variation in wages, income, and family size. We use both quasi-experimental and reduced-form labor supply models to estimate the impact of EITC-induced tax changes. The results suggest that EITC expansions between 1984 and 1996 increased married men’s labor force participation only slightly but reduced married women’s labor force participation by over a full percentage point. Overall, the evidence suggests that family labor supply and pre-tax family earnings fell among married couples. Our results imply that the EITC is effectively subsidizing married mothers to stay at home, and therefore have implications for the design of the program.

Biomarcadores etológicos no invasivos de estrés ambiental: estudio comparativo en dos teleosteos de ecosistemas de la región pampeana argentina

Mediante un dispositivo de registro automático se estudió el efecto de la exposición a soluciones subletales de Cd2+ (0.3 mg. L'1) sobre algunos parámetros etológicos de juveniles de Cyprinus carpió (carpa común) y de Astyanax fasciatus (“mojarra”). Se evaluó el efecto del metal sobre la actividad natatoria total y las preferencias altitudinales y laterales de los peces. Los tres parámetros se registraron simultáneamente mediante un dispositivo original. Se evaluaron los niveles “normales” o estándar de dichos parámetros (los peces en agua potable, control) y los alcanzados por los mismos individuos tras su exposición al tóxico de referencia (Cd). El metal provocó una depresión de la actividad natatoria total alcanzando una magnitud comparable en ambas especies. La preferencia altitudinal, también resultó modificada: C. carpió se halló con mayor frecuencia en la capa superior de los acuarios mientras que A. fasciatus se ubicó en las inferiores. En cuanto a la preferencia lateral, los individuos de ambas especies evitaron la franja vertical donde se producía el goteo de la solución de Cd; si bien esta respuesta espacial de los animales no siguió un patrón definido fue más marcada en las carpas. Todas las respuestas se pusieron de manifiesto inmediatamente después de haberse iniciado la exposición al Cd. El método resultó sensible y apto para el seguimiento de los parámetros etológicos seleccionados. Se concluye que la actividad natatoria y la ubicación espacial de las especies estudiadas, entre otros indicadores, pueden ser considerados como biomarcadores de toxicidad acuática.By means of an automatic recording device, the eífects of the exposure to sublethal Solutions of Cd2+ (0.3 mg. L2) on some ethological parameters of juvenile Cyprinus carpió (common carp) and Astyanaxfasciatus. The effect of the metal was evaluated through three parameters: the total swimming activity and the spatial (lateral and altitudinal) preferences, relative to Controls (fish kept in tap water); they were registered simultaneously by means oían original device. There were determined successively the “normal” or standard levels of those parameters in control fish and those reached by the same individuáis aftertheir exposure to thereferencetoxic (Cd). In both species the metal caused a depression of the total swimming activity in a comparable magnitude. The altitudinal preference was also modified: C. carpió was found more frequently in the superior layer of the aquaria while A. fasciatus was found in the inferior ones. For the lateral preference, the individuáis of both species showed an avoidance behavior of the site of the aquaria where the Cd Solutions was dripping. This response of the animáis didn't follow a defined pattem, but was more marked in the carps. All the evaluated responses to the toxic were detected immediately after the beginning of the exposure to Cd. The method proved to be sensitive and apt for the monitoring of the measured behavioural parameters which makes it a promising tool for biomonitoring purposes. We concluded that the swimming activity and the spatial location preferences of the studied species, among other, may be considered as biomarkers of aquatic toxicity

Electrical resistivity tomography array comparisons to detect cleared-wall foundations in brownfield sites

Electrical resistivity surveys are commonly used to detect and characterise near-surface buried objects in commercial developments of brownfield sites. 2D ERT profiles arrays predominate in such surveys due to their relatively rapid deployment, good penetration depths and fast data collection rates. However, there is a need to test the optimum array types in such surveys. A scaled-model was used to simulate a large cleared-building wall foundation at a test facility, before multiple 2D ERT profiles were acquired using different array configurations. Results were used to generate 2D resistivity models using both least-square smoothness-constraint and robust inversion. 2D profile array comparisons showed that the Wenner and dipole-dipole arrays were the best in detecting the cleared-wall foundation, although dipole-dipole arrays better delineated the top of the wall foundation. This study suggests that both Wenner and dipole-dipole array configurations should be utilised to detect buried wall foundations for 2D resistivity surveys

INFORMATION OVERLOAD AND INDIVIDUAL INVESTORS’ PERCEPTIONS OF INVESTMENT RISK: EVIDENCE FROM SAUDI ARABIA

This study explores investors’ perceptions of investment risk under information overload. We use a survey of 133 individual investors in the Kingdom of Saudi Arabia (KSA), and to test our hypotheses, we employ descriptive statistics and sample t-test. We found that information overload in lengthy annual reports decreases investors’ confidence in the financial statements and reduces their ability to understand the firm’s business and financial performance. Investors confirmed that information overload reduces their ability to access relevant information for making investment decisions and predict future performance, and increases uncertainty about the firms’ future performance. Consequently, information overload increases investors’ perceptions of firms’ investment risk, reduces their confidence to invest in firms with long and difficult-to-read annual reports, and increases their perceptions of the likelihood that these reports are being exploited by managers to hide poor performance or earnings manipulation, and consequently, they prefer not to invest in these firms. In addition, the results indicated that disclosure complexity along with information overload exacerbates investors’ negative perceptions about the firm’s investment risk and its performance. Our results provide insights for investors in emerging markets such as the Saudi market to understand the negative implications of information overload, which can enlighten their investment decisions

Transmitters and receivers in SiGe BiCMOS technology for sensitive gas spectroscopy at 222 - 270 GHz

This paper presents transmitter and receiver components for a gas spectroscopy system. The components are fabricated in IHP's 0.13 μm SiGe BiCMOS technology. Two fractional-N phase-locked loops are used to generate dedicated frequency ramps for the transmitter and receiver and frequency shift keying for the transmitter. The signal-to-noise ratio (SNR) for the absorption line of gaseous methanol (CH 3 OH) at 247.6 GHz is used as measure for the performance of the system. The implemented mixer-first receiver allows a high performance of the system due to its linearity up to an input power of -10 dBm. Using a transmitter-array with an output power of 7 dBm an SNR of 4660 (integration time of 2 ms for each data point) was obtained for the 247.6 GHz absorption line of CH 3 OH at 5 Pa. We have extended our single frequency-band system for 228 - 252 GHz to a 2-band system to cover the range 222 - 270 GHz by combining corresponding two transmitters and receivers with the frequency bands 222 - 256 GHz and 250 - 270 GHz on single transmitter- and receiver-chips. This 2-band operation allows a parallel spectra acquisition and therefore a high flexibility of data acquisition for the two frequency-bands. The 50 GHz bandwidth allows for highly specific and selective gas sensing. © 2019 Author(s)

Advanced diagnosis of vibriosis among some marine fishes in lake Temsah, Egypt

ΔΕΝ ΔΙΑΤΙΘΕΤΑΙ ΠΕΡΙΛΗΨΗVibriosis is a serious disease affecting marine water fishes. The present study was applied on 320 marine fishes of four equal different species (Sparus auratus, Mugil cephalus, Mugil seheli and Tilapia zillii) each 80. Fishes were collected seasonally and randomly from Lake Temsah in Ismailia governorate from September2015 to August 2016. The signs and lesions of severe septicemia, hemorrhages and ulcerations were observed among the examined fishes. Isolated bacteria were observed as yellow and green pigmented colonies on TCBS media, and as creamy colored colonies on TSA media with 2.5% NaCl concentration. The causative agent was identified as vibrio sp. Concerning gene expression, most isolates were molecularly identified using the pvsA gene primers giving a product size of 338-bp size and 348-bp for V. alginolyticus and V. parahemolyticus respectively. The highest prevalence of vibriosis was recorded in T. zillii (63.75%), M.seheli (37.5%) then M.cephalus and Sparus auratus (28.75%) while the total prevalence was (39.69%). The highest seasonal prevalence was recorded in summer (81.25%) followed by spring (35%) then autumn (23.75%) and winter (18.75%). The highest prevalence of organ specifity was in liver, kidneys then spleen and gills. The histopathological studies showed activation of melanomacrophage centers, degeneration, necrosis and congestion in liver, kidney, spleen, and gills

Propuesta guía para una planeación y ejecución en proyectos de vivienda unifamiliar con enfoque Lean Construction

Trabajo de investigaciónEste trabajo contempla el desarrollo de una matriz enfocada en la metodología Lean Construction para la planeación y ejecución en proyectos de vivienda unifamiliar. Así mismo se evidencia un análisis de manera cuantitativa y cualitativamente en la adopción de la filosofía Lean Construction en procesos de la gestión de la planeación y ejecución de proyectos, que permite establecer un orden de actividades y sub actividades que componen las fases de un proyecto de vivienda unifamiliar en la relación del alcance exitoso en productividad y rendimiento.INTRODUCCIÓN 1. GENERALIDADES 2. METODOLOGÍAS EN EL MARCO DE LA PLANEACIÓN Y EJECUCIÓN DE PROYECTOS 3. LEAN CONSTRUCTION EN ACTIVIDADES DE CONSTRUCCIÓN 4. IMPLEMENTACIÓN DE LA MATRIZ EN CASO DE ESTUDIO 5. CONCLUSIONES 6. RECOMENDACIONES BIBLIOGRAFÍA ANEXOSPregradoIngeniero Civi

Dual-Band Transmitter and Receiver with Bowtie-Antenna in 0.13 μm SiGe BiCMOS for Gas Spectroscopy at 222 - 270 GHz

This paper presents a transmitter (TX) and a receiver (RX) with bowtie-antenna and silicon lens for gas spectroscopy at 222-270 GHz, which are fabricated in IHP’s 0.13 μm SiGe BiCMOS technology. The TX and RX use two integrated local oscillators for 222 – 256 GHz and 250 – 270 GHz, which are switched for dual-band operation. Due to its directivity of about 27 dBi, the single integrated bowtie-antenna with silicon lens enables an EIRP of about 25 dBm for the TX, and therefore a considerably higher EIRP for the 2-band TX compared to previously reported systems. The double sideband noise temperature of the RX is 20,000 K (18.5 dB noise figure) as measured by the Y-factor method. Absorption spectroscopy of gaseous methanol is used as a measure for the performance of the gas spectroscopy system with TX- and RX-modules