Do Non-standard Working Hours Cause Negative Health Effects? Some Evidence from Panel Data

What does the around-the-clock economic activity mean for workers’ health? Despite the fact that non-standard work accounts for an increasing share of the job opportunities, relatively little is known about the potential consequences for health and the existing evidence is ambiguous. In this paper I examine the relationship between non-standard job schedules and workers’ physical and mental health outcomes using longitudinal data from the Household, Income and Labour Dynamics in Australia (HILDA). Specifically, the four health indicators considered are self-rated health and the SF-36 health indices for general health, mental health and physical functioning. In terms of direction of the effects, overall results generally suggest a negative relationship between non-standard work schedules and better health for both males and females. Regarding the statistical significance and magnitudes of the effects, however, we observe apparent differences between males and females. Among females, most of the coefficients in all models are statistically insignificant, which implies very small magnitudes in terms of the correlation between non-standard working hours and health. These results apply uniformly to all health measures investigated. Among males, on the other hand, the negative relationship is more noticeable for self-rated health, general health and physical functioning than for mental health. The pooled OLS and random effects coefficients are usually larger in magnitude and more significant than the fixed effects parameters. Nonetheless, even the more significant coefficients, fortunately, do not imply large effects in absolute terms.Non-standard work, physical health, mental health

Notes on the Merger Strategy of High versus Low-tech Industries: Complementarities and Moral Hazard

In this essay I assess the role that is played by the two characteristics of high-tech firms in shaping their corporate strategies: short product cycles and the involvement of intangible assets in production. Short product cycles impose high-tech firms to seek complementary assets for entering new markets quickly and compete. The involvement of intangible capital in high-tech production, on the other hand, is related to the distinguishing characteristic of high-tech industries for which R&D activities are observed frequently and firms employ a large proportion of scientists, engineers and technicians. In this essay, I hypothesize and show that as a result of these two characteristics high-technology firms are likely to engage in vertical mergers more often than low-technology firms and vertical mergers are likely to involve firms that employ intangible assets in production.complementarities

Consumption Patterns around the Time of Retirement: Evidence from the Consumer Expenditure Surveys

This study,using the Consumer Expenditure Surveys from 1984 through 1998, revisits the widely pronounced retirement-savings puzzle, which claims the existence of a sharp drop in consumption at the time of retirement. In contrast to previous work, I find that consumption of the retired households is consistent with the smoothing behavior implied by the conventional permanent income/life-cycle models. The results present evidence that the elderly actually do not reduce their standard of living around the time of retirement due to a shortage in savings or some other reasons. While the evidence does not favor a dramatic drop in consumption, the composition of consumption changes significantly as households move into the retirement period. The difference between the results of this study and those of the previous work is mainly driven by the fact that I use a comprehensive measure of consumption that includes not only nondurables and services but also service flows from housing and durables. Moreover, using detailed information on the prices faced by the households yields a more accurate measure of household consumptionConsumption, Well-being of the Elderly, Retirement

Maskless imaging of dense samples using pixel super-resolution based multi-height lensfree on-chip microscopy.

Lensfree in-line holographic microscopy offers sub-micron resolution over a large field-of-view (e.g., ~24 mm2) with a cost-effective and compact design suitable for field use. However, it is limited to relatively low-density samples. To mitigate this limitation, we demonstrate an on-chip imaging approach based on pixel super-resolution and phase recovery, which iterates among multiple lensfree intensity measurements, each having a slightly different sample-to-sensor distance. By digitally aligning and registering these lensfree intensity measurements, phase and amplitude images of dense and connected specimens can be iteratively reconstructed over a large field-of-view of ~24 mm2 without the use of any spatial masks. We demonstrate the success of this multi-height in-line holographic approach by imaging dense Papanicolaou smears (i.e., Pap smears) and blood samples

Lensfree super-resolution holographic microscopy using wetting films on a chip.

We investigate the use of wetting films to significantly improve the imaging performance of lensfree pixel super-resolution on-chip microscopy, achieving < 1 µm spatial resolution over a large imaging area of ~24 mm(2). Formation of an ultra-thin wetting film over the specimen effectively creates a micro-lens effect over each object, which significantly improves the signal-to-noise-ratio and therefore the resolution of our lensfree images. We validate the performance of this approach through lensfree on-chip imaging of various objects having fine morphological features (with dimensions of e.g., ≤0.5 µm) such as Escherichia coli (E. coli), human sperm, Giardia lamblia trophozoites, polystyrene micro beads as well as red blood cells. These results are especially important for the development of highly sensitive field-portable microscopic analysis tools for resource limited settings

Holographic opto-fluidic microscopy.

Over the last decade microfluidics has created a versatile platform that has significantly advanced the ways in which micro-scale organisms and objects are controlled, processed and investigated, by improving the cost, compactness and throughput aspects of analysis. Microfluidics has also expanded into optics to create reconfigurable and flexible optical devices such as reconfigurable lenses, lasers, waveguides, switches, and on-chip microscopes. Here we present a new opto-fluidic microscopy modality, i.e., Holographic Opto-fluidic Microscopy (HOM), based on lensless holographic imaging. This imaging modality complements the miniaturization provided by microfluidics and would allow the integration of microscopy into existing on-chip microfluidic devices with various functionalities. Our imaging modality utilizes partially coherent in-line holography and pixel super-resolution to create high-resolution amplitude and phase images of the objects flowing within micro-fluidic channels, which we demonstrate by imaging C. elegans, Giardia lamblia, and Mulberry pollen. HOM does not involve complicated fabrication processes or precise alignment, nor does it require a highly uniform flow of objects within microfluidic channels

Spatial Proximity and Complementarities in the Trading of Tacit Knowledge

We model knowledge-trading coalitions in which the transfer of tacit knowledge is unverifiable and requires face-to-face contact, making spatial proximity important. When there are sufficient “complementarities” in knowledge exchange, successful exchange is facilitated if firms can meet in a central location,thereby economizing on travel costs. When complementarities are small,however, a central location may be undesirable because it is more vulnerable to cheating than a structure involving bilateral travel between firms. We believe that our framework may help explain the structure and stability of multimember technology trading coalitions such as Sematech and Silicon Valley.Tacit Knowledge, Clusters, Knowledge Trading, Complementarities. Spatial Proximity

On-chip differential interference contrast microscopy using lensless digital holography.

We introduce the use of a birefringent crystal with lensless digital holography to create an on-chip differential interference contrast (DIC) microscope. Using an incoherent source with a large aperture, in-line holograms of micro-objects are created, which interact with a uniaxial crystal and an absorbing polarizer, encoding differential interference contrast information of the objects on the chip. Despite the fact that a unit fringe magnification and an incoherent source with a large aperture have been used, holographic digital processing of such holograms rapidly recovers the differential phase contrast image of the specimen over a large field-of-view of approximately 24 mm(2)

Are Covid-19 Cases Independent of the City Sizes?

In this paper it is shown that more crowded cities did not exacerbate the Covid-19 pandemic. Reports from Turkey constitutes evidence that the Gibrat’s Law holds and the infection grows among population in proportion to the city sizes. Covid-19 cases are lognormally distributed throughout the country. While the 0-19 age group of the society is associated with a negative impact on the reported cases, 40-59 group has the most additive effect. Distribution of the reported deaths from Covid-19 does not grow in proportion to the city size, and may well be approximated by both exponential and normal distributions