A monte carlo analysis of the type II tobit maximum likelihood estimator when the true model is the type I tobit model

Type I (censored regression) and Type II Tobit (sample selection) models are widely used in the various fields of economics. The Type I Tobit model is a special case of the Type II Tobit model. However, the dimension of the error terms decreases and the distribution of the error terms degenerates in the Type I Tobit Model. Therefore, we cannot use the standard asymptotic theorems for the Type II Tobit Maximum Likelihood Estimator (MLE) when the sample is obtained from the Type I Tobit model. Results of Monte Carlo experiments show strange behavior that has never been reported before for the Type II MLE.

Risk factors for heart, cerebrovascular, and kidney diseases: evaluation of potential side effects of medications to control hypertension, hyperglycemia, and hypercholesterolemia

BackgroundHeart disease (HD), cerebrovascular disease (CBD), and kidney disease (KD) are serious diseases worldwide. These diseases constitute the leading causes of death worldwide and are costly to treat. An analysis of risk factors is necessary to prevent these diseases.Data and MethodsRisk factors were analyzed using data from 2,837,334, 2,864,874, and 2,870,262 medical checkups obtained from the JMDC Claims Database. The side effects of medications used to control hypertension (antihypertensive medications), hyperglycemia (antihyperglycemic medications), and hypercholesterolemia (cholesterol medications), including their interactions, were also evaluated. Logit models were used to calculate the odds ratios and confidence intervals. The sample period was from January 2005 to September 2019.ResultsAge and history of diseases were found to be very important factors, and the risk of having diseases could be almost doubled. Urine protein levels and recent large weight changes were also important factors for all three diseases and made the risks 10%–30% higher, except for KD. For KD, the risk was more than double for individuals with high urine protein levels. Negative side effects were observed with antihypertensive, antihyperglycemic, and cholesterol medications. In particular, when antihypertensive medications were used, the risks were almost doubled for HD and CBD. The risk would be triple for KD when individuals were taking antihypertensive medications. If they did not take antihypertensive medications and took other medications, these values were lower (20%–40% for HD, 50%–70% for CBD, and 60%–90% for KD). The interactions between the different types of medications were not very large. When antihypertensive and cholesterol medications were used simultaneously, the risk increased significantly in cases of HD and KD.ConclusionIt is very important for individuals with risk factors to improve their physical condition for the prevention of these diseases. Taking antihypertensive, antihyperglycemic, and cholesterol medications, especially antihypertensive medications, may be serious risk factors. Special care and additional studies are necessary to prescribe these medications, particularly antihypertensive medications.LimitationsNo experimental interventions were performed. As the dataset was comprised of the results of health checkups of workers in Japan, individuals aged 76 and above were not included. Since the dataset only contained information obtained in Japan and the Japanese are ethnically homogeneous, potential ethnic effects on the diseases were not evaluated

Did the Credit Crunch in Japan Affect Household Welfare? An Augmented Euler Equation Approach Using Type 5 Tobit Model

We investigate whether the credit crunch in Japan affected household welfare and the manner in which it did. We augment the theoretical framework of a consumption Euler equation with endogenous credit constraints and estimate it with household panel data for 1993-1999, generating several empirical findings. First, a small portion of the people faced credit constraints in Japan before and after the financial crisis in 1997. Accordingly, our results reject the standard consumption Euler equation. Second, the credit crunch affected household welfare negatively, albeit not seriously, after 1997. Our results corroborate that the credit crunch in Japan was supply-driven.

"Did the Credit Crunch in Japan Affect Household Welfare? An Augmented Euler Equation Approach Using Type 5 Tobit Model"

We investigate whether the credit crunch in Japan affected household welfare and the manner in which it did. We augment the theoretical framework of a consumption Euler equation with endogenous credit constraints and estimate it with household panel data for 1993-1999, generating several empirical findings. First, a small portion of the people faced credit constraints in Japan before and after the financial crisis in 1997. Accordingly, our results reject the standard consumption Euler equation. Second, the credit crunch affected household welfare negatively, albeit not seriously, after 1997. Our results corroborate that the credit crunch in Japan was supply-driven.

The maximum Number of parameters for the Hausman Test When the Estimators are from Different Sets of Equations

__Abstract__ Hausman (1978) developed a widely-used model specification test that has passed the test of time. The test is based on two estimators, one being consistent under the null hypothesis but inconsistent under the alternative, and the other being consistent under both the null and alternative hypotheses. In this paper, we show that the asymptotic variance of the difference of the two estimators can be a singular matrix. Moreover, in calculating the Hausman test there is a maximum number of parameters which is the number of different equations that are used to obtain the two estimators. Three illustrative examples are used, namely an exogeneity test for the linear regression model, a test for the Box-Cox transformation, and a test for sample selection bias

Contract Workers in Japan's Nuclear Utility Industry: Can We Maintain Safety and Health Standards at Nuclear Power Plants?

: Many small contracting firms are used to maintain nuclear power plants in Japan. The accident at the Fukushima nuclear plant raised the serious question as to whether safety standards can be upheld with this system. A review of regulations governing Japan's nuclear utility industry derived two imperfect information models that implied opposing incentives for utility companies to use contract workers rather than hire employees. We then analyzed the dataset of nuclear plant worker's exposure to radiation in the power generation industry. The results suggest that using contract workers enables the utility companies to implement lower standards than those imposed by regulations and to reduce costs by circumventing responsibilities legally imposed on employers