Effects of Disease Type and Latency on the Value of Mortality Risk

We evaluate the effects of disease type and latency on willingness to pay (WTP) to reduce environmental risks of chronic, degenerative disease. Using contingent-valuation data collected from approximately 1,200 respondents in Taiwan, we find that WTP declines with latency between exposure to environmental contaminants and manifestation of any resulting disease, at a 1.5 percent annual rate for a 20 year latency period. WTP to reduce the risk of cancer is estimated to be about one-third larger than WTP to reduce risk of a similar chronic, degenerative disease. The value of risk reduction also depends on the affected organ, environmental pathway, or payment mechanism: estimated WTP to reduce the risk of lung disease due to industrial air pollution is twice as large as WTP to reduce the risk of liver disease due to contaminated drinking water.

Maximum Score Estimates of the Determinants of Residential Mobility: Implications for the Value of Residential Attachment and Neighborhood Amenities

This paper examines the determinants of the decision of low-income renters to move out of their current dwelling. Maximum score estimation is shown t be superior to ordinary discrete choice estimation techniques (probit, logit) for this problem, ad for similar discrete choices that require revering a previously optimal decision. The estimation reveals psychological costs of moving for typical low income renters of at least 8 percent of their income; these costs are even higher for older, longer tenure, or minority households. Policies that displace low income renters will have large social costs. In addition, the estimation results are used to calculate implicit household willingness to pay (WTP) for neighborhood amenities. This WTP based on mobility behavior is much greater than WTP estimates derived using hedonic methods, and is argued to be more accurate. This paper uses a semiparametric empirical technique to estimate the determinants of the decision of low-income renters to move out of their dwelling. These estimates show that low-income residents highly value remaining in their dwelling. In addition, these estimates are used to illustrate an alternative method to measure willingness to pay for neighborhood amenities. Moving decisions are usually examined with standard discrete choice models such as probit or logit (e.g., Venti and Wise (1984), or Weinberg, Friedman, and Mayo (1981). But the moving decision presents econometric difficulties for standard discrete choice models. As will be explained in section 1, because the household decision about moving is conditional on having previously preferred the original location, the disturbance term in mobility models is unlikely to follow the simple distributional forms required for probit or logit estimation. Maximum score estimation is an alternative estimation technique for discrete choice models that is robust to unusual distributions of the disturbance term. Although the theoretical properties of maximum score estimation have been well-explored (see Manski (1975,1985)), our paper presents one of the first empirical applications of maximum score techniques. Maximum score estimation of our residential mobility model yields similar parameter estimates to probit estimation, but much smaller standard errors. This advantage of greater precision may prove attractive to other researchers. We use our estimates of the residential mobility model to calculate the value to households of remaining at their current dwelling rather than being forced to move out. We use the household's mobility response to rent changes to infer a monetary value of remaining in the current dwelling. Our calculations indicate that the typical low-income renter household is willing to pay at least 8 percent of its annual income to avoid being forced out of its current dwelling. These "psychological moving costs" increase greatly for older or longer tenure households. Large "psychological moving costs" have important implications for public policy towards low-income neighborhoods. Neighborhood improvement policies or private market forces may displace low-income renters. If the losses suffered by low-income renters due to being forced out of their current dwelling unit are significant, as indicated in this paper, then it is important to include these losses in any evaluation of the net benefits of a neighborhood improvement program. In addition, policy makers might want to consider policies to prevent or compensate for privately-induced displacement. Estimates of the monetary value of low-income renters' psychological moving costs are important to determining the effects of these policies, and deciding appropriate compensation. Finally, this paper uses the residential mobility estimates to infer the willingness t pay (WTP) of low-income renters for neighborhood amenities such as the physical condition of the neighborhood, neighborhood school quality, and the safety of the neighborhood from crime. The relative responsiveness of household mobility to changes in these neighborhood amenities, versus changes in rents, implicitly reveals households' monetary valuations of these amenities. The more common approach to measuring household WTP for neighborhood amenities is the hedonic price approach, which relies n the equilibrium relationship between housing prices and amenities. The calculations in this paper suggest that mobility-based WTP estimates for amenities may often be greater than hedonic based estimates of WTP. We consider which approach is more accurate. Section 1 of the paper presents our econometrics, specification, and data. Section 2 presents the results. Section 3 is the conclusion.residential, mobility, determinants, Bartik, low-income, renters

Orientation-dependent bending properties of selectively-filled photonic crystal fibres

A selective-filling technique was demonstrated to improve the optical properties of photonic crystal fibres (PCFs). Such a technique can be used to fill one or more fluid samples selectively into desired air holes. The technique is based on drilling a hole or carving a groove on the surface of a PCF to expose selected air holes to atmosphere by the use of a micromachining system comprising of a femtosecond infrared laser and a microscope. The exposed section was immersed into a fluid and the air holes are then filled through the well-known capillarity action [1, 2]. Provided two or more grooves are fabricated on different locations and different orientation along the fibre surface, different fluids may be filled into different air-holes to form a hybrid fibre. As an example, we filled half of a pure-silica PCF by a fluid with n=1.480 by carving a rectangular groove on the fibre (Figure 1). Consequently, the half-filled PCF became a bandgap-guiding structure (upper half), resulted from a higher refractive index in the fluid rods than in the fibre core [3], and three bandgaps were observed within the wavelength range from 600 to 1700 nm. Whereas, the lower half (unfilled holes) of the fibre remains an air/silica index-guiding structure (Figure 1(b)). When the hybrid PCF is bent, its bandgaps gradually narrowed, resulted from the shifts of the bandgap edges. The bandgap edges had distinct bend-sensitivities when the hybrid PCF was bent toward different directions. Especially, the bandgaps are hardly affected when the half-filled PCF was bent toward the fluid-filled region. Such unique bend properties could be used to monitor simultaneously the bend directions and the curvature of the engineering structures

The Intergenerational Transmission of Education: Evidence from Taiwanese Adoptions

This paper examines the causal effect of parental schooling on children’s schooling using a large sample of adoptees from Taiwan. Using birth-parents’ education to help control for selective placement of children with adoptive parents, we find that adoptees raised with more highly educated parents have higher educational attainment, measured by years of schooling and probability of university graduation. We also find evidence that adoptive father’s schooling is more important for sons’ and adoptive mother’s schooling is more important for daughters’ educational attainment. These results support the notion that family environment (nurture) is important in determining children’s educational outcomes, independent of genetic endowment.intergenerational transmission, education, schooling, adoption

Selectively fluid-filled microstructured optical fibers and applications

A versatile technique based on micromachining is demonstrated to fill selectively one or several different types of fluids into desired air holes in a microstructured optical fiber (MOF). Unique optical properties and applications of the selective-filled MOF are investigated

GLOBAL WELL-POSEDNESS FOR THE HALL-MAGNETOHYDRODYNAMICS SYSTEM IN LARGER CRITICAL BESOV SPACES

We prove the global well-posedness of the Cauchy problem to the 3D incompressible Hall-magnetohydrodynamic system supplemented with initial data in critical Besov spaces, which generalize the result in [10]. Meanwhile , we analyze the long-time behavior of the solutions and get some decay estimates. Finally, a stability theorem for global solutions is established

The Impact of Sibling Sex Composition on Women's Educational Achievements: A Unique Natural Experiment by Twins Gender Shocks

In a pro-male biased society, brothers may reduce the parental investment received by female siblings, if parents face time or financial constraints. But brothers may also cause positive externalities. Using more than 12,000 firstborn twins from a highly sex-imbalanced economy, Taiwan, we test if women have fewer opportunities to attend college if they have a brother rather than a sister. To minimize the problem of sex selection, we exploit the fact that twin sex is random given the sex of the other twin, once we limit the data to time periods in which abortion was illegal and technology was unavailable to abort one of the two twins. We show that the birth of a male sibling, relative to a female, has almost no impact on women's or men's college enrollments on the average. If there is any effect, it is small and imprecise. Our results point to the importance of accounting for positive externalities (e.g., decreasing family size) created by a son's birth, in studies on sibling rivalry.education, son preference, sibling rivalry, sibling spillover, sex selective abortion, within-family allocation of resources

As Low Birth Weight Babies Grow, Can 'Good' Parents Buffer this Adverse Factor? A Research Note.

This research note combines two national Taiwanese datasets to investigate the relationship between low birth weight (LBW) babies, their family background and their future academic outcomes. We find that LBW is negatively correlated with the probability of such children attending university at the age of 18; however, when both parents are college or senior high school graduates, such negative effects may be partially offset. We also show that discrimination against daughters does occur, but only in those cases where the daughters were LBW babies. Moreover, high parental education (HPE) can only buffer the LBW shock among moderately-LBW children (as compared to very-LBW children) and full term-LBW children (as compared to preterm-LBW children).

Parental Education and Child Health: Evidence from a Natural Experiment in Taiwan

This paper exploits a natural experiment to estimate the causal impact of parental education on child health in Taiwan. In 1968, the Taiwanese government extended compulsory education from six to nine years. From that year through 1973, the government opened 254 new junior high schools, an 80 percent increase, at a differential rate among regions. We form treatment and control groups of women or men who were age 12 or under on the one hand and between the ages of 13 and 20 or 25 on the other hand in 1968. Within each region, we exploit variations across cohorts in new junior high school openings to construct an instrument for schooling. We employ this instrument to estimate the causal effects of mother's or father's schooling on the incidence of low birthweight and mortality of infants born to women in the treatment and control groups or the wives of men in these groups in the period from 1978 through 1999. Parents' schooling, especially mother's schooling, does indeed cause favorable infant health outcomes. The increase in schooling associated with the reform saved almost 1 infant life in 1,000 live births, resulting in a decline in infant mortality of approximately 11 percent.

Valuation of the Risk of SARS in Taiwan

Two surveys conducted in Taiwan during the spring 2003 SARS epidemic reveal a high degree of concern about the threat posed by SARS to Taiwan and to residents, although respondents believe they are knowledgeable about the risk of SARS and that it is susceptible to individual control. WTP to reduce the risk of infection and death from SARS is elicited using contingent valuation methods. Estimated WTP is high, implying values per statistical life of US$3 to 12 million. While consistent with estimates for high-income countries, these values are substantially larger than previous estimates for Taiwan and may be attributable to the high degree of concern about SARS at the time the data were collected.