Aziz Hayat

Comparison of Estimators of the Weibull Distribution

We compare the small sample performance (in terms of bias and root mean squared error) of the L-moment estimator of a three-parameter Weibull distribution with maximum likelihood estimation (MLE), moment estimation (MoE), least-square estimation (LSE), the modified MLE (MMLE), the modified MoE (MMoE), and the maximum product of spacing (MPS). Overall, the LM method has a tendency to perform well as it is almost always close to the best method of estimation. The ML performance is remarkable even at a small sample size of n = 10 when the shape parameter β lies in the [1.5, 4] range. The MPS estimator dominates others when 0.5 ≤ β < 1.5. For large β ≥ 6, MMLE outweighs others in samples of size n ≥ 50, whereas LM is preferred in samples of size n ≤ 20.

WHY DO CHILDREN TAKE CARE OF THEIR ELDERLY PARENTS? ARE THE JAPANESE ANY DIFFERENT?: WHY DO CHILDREN TAKE CARE?

We conduct a theoretical and empirical analysis of why children live with (or near) their parents and provide care and assistance to them using microdata from a Japanese household survey, the Osaka University Preference Parameter Study. We find that the Japanese are more likely to live with (or near) their elderly parents and/or to provide care and attention to them if they expect to receive a bequest from them, which constitutes strong support for the strategic bequest motive, but that their caregiving behavior is also heavily influenced by the strength of their altruism toward their parents and social norms.