Standard error and confidence interval for QALY weights

There are some problems with the standard errors of QALY weights proposed by Groot (2000, Journal of Health Economics 19). The standard errors show smaller values than those of Groot when we recalculate using his method. Moreover, we correct the derivation of his approximation and derive corrected values. Because mean and variance do not exist for a distribution of QALY weights, using standard errors for statistical inference may lead to problems even when an approximation is used. In this paper, we verify the statistical properties of Groot's standard errors by simulation. We find that the corrected standard errors hold the same properties as a normal distribution under specific conditions. In general, however, it would be appropriate to use our simulation method to obtain critical values or p-value.

The effect of hospital medical services on child mortality in Japan

The purpose of this paper is to conduct a fact-finding study on how differences in the supply of medical care affect the cause-specific mortality among children aged 1 to 4 years in Japan. We find that the supply of emergency medical care in hospitals has a significant negative effect on the mortality. Furthermore, the availability of primary emergency care at hospitals on weekend nights has a significant negative effect on the mortality owing to either external or internal causes. Finally, the availability of physicians has a more pronounced effect on mortality from external causes than from internal causes

Informal and formal care for elderly persons: How adult children's characteristics affect the use of formal care in Japan

Informal care by adult children remains the most common source of caregiving for elderly parents in Japan, even after the introduction of long-term care insurance in 2000. We estimate how the potential supply of child caregivers affects the use of formal care of elderly parents, focusing on the differences across children. We find that the effects of children's presence vary substantially with gender, marital status, and opportunity costs of children. The potential supply of daughters-in-law, as the traditional source of informal care, is less important in providing care than that of unmarried children. The opportunity costs of children make a difference in the use of formal long-term care.Japan Informal care Long-term care insurance Aging Daughters-in-law

Temporal instability of risk preference among the poor: Evidence from payday cycles

The poor live paycheck to paycheck and are repeatedly exposed to strong cyclical income fluctuations. We investigate whether such income fluctuations affect risk preference among the poor. If risk preference temporarily changes around payday, optimal decisions made before payday may no longer be optimal afterward, which could reinforce poverty. By exploiting Social Security payday cycles in the US, we find that risk preference among the poor relying heavily on Social Security changes around payday. Rather than cognitive decline before payday, the deterioration of mental health and relative deprivation may play a role. We find similar evidence among the Japanese elderly