The rates of suicide to all deaths, or suicide mortality rates in Japan, observed in time series, show cyclic changes with high and low rates occurring alternately throughout the pre-and post-war periods. The number of suicides correlates to changes in social environment. It was on a high level during the pre-war panic age of rural communities (1932-1933), recorded an extraordinary low value during the Second World War, rose suddenly with the unprecedented prosperity of post-war days, dropped gradually as the Japanese economy was entering a stable, growth period (in the latter half of 1960's), remained at a relatively low rate after that, and went up sharply in 1983 and posed a social problem.
In Japan, suicide mortality is higher in agricultural districts than in urban areas, and is higher among full-time farmers than part-time farmers. In developed countries in the West, it is higher in big cities. This difference is remarkable.
We performed a multiple regression analysis to examine the relationship of suicide mortality and some socio-economic factors using data in 1985 when suicide mortality was still on a high level. The age-adjusted suicide mortality of each prefecture was given as an object variable and the explanatory variables included such socio-economic factors as income index per capita and mobility ratio of each prefecture. Added to these were the number of persons who died of illness and the number of psychotics as indices of desease and psychopathy which could be regarded, as the main motives for committing suicide.
The outcome was that a multiple regression formula with the social economic factors held as an estimator. The two facors, per capita income index and social mobility ratio, were significant explanatory variables, and proved to be important social economic elements concerning the sharp increase in suicide mortality.

Forty-nine years have passed since the agricultural cooperative started life insurance business in 1952. Right from the start, it expanded by leaps and bounds. As of the end of fiscal 1999, the total number of contracts amounted to 13, 350, 000 cases for endowment insurance and 4, 240, 000 cases for whole life insurance. The average value of death benefits per policy came to ¥12, 000, 000 for former and ¥21, 000, 000 for the latter. Worthy of special mention is the fact that a considerably large sum of money is assured to a beneficiary designated by the owner of a whole life insurance policy.
We made analyses of mortality rates and causes of death among insureds over a period of 20 years from 1980, using the agricultural cooperative life insurance statistics.
Broadly, deaths from strokes and accidents were on the decline. This was probably attributable to individuals' efforts at prevention. By contrast, mortality rates for malignant neoplasms tended to increase year after year. Especially lung cancer and liver cancer rates were being on a sharp upward curve, whereas cancer of the stomach tended to claim less lives in recent years. In the present study, we picked up 16 prefectures and carried out a longitudinal study of data on the mortalities for the abovementioned three types of cancer.

In the insured of the agricultural cooperative life insurance program (12, 156, 022 cases), 12, 588 persons were involved in accidents in 1973 fiscal year. The following analysis was conducted on these 12, 588 persons with special reference to the 2, 218 persons who were involved in farm machine accidents.
1. There were 3, 945 cases of traffic accidents. Of them, there were 2, 499 deaths and the fatality ratio stood at as high as 63.3%. There were 57 cases of traffic accidents involving farm machines. Of them, there were 42 deaths and the fatality rate was evidently high with 73.6%
2. There were 54 deaths caused by farm machines excluding those caused by traffic accidents. Of them, 45 were caused by cultivators. The ratio was extremely high with 83.3%.
3. Of the 45 deaths caused by cultivators, 26 were the cases in which the operators were pressed by fallen cultivators. In 13 cases, the operators were caught in between the machine and tree or building.
4. There were the other 2, 164 cases of farm machine accidents in which the patients were later seized with sequelae. Of these cases, 564 cases (26.0%) were caused by cultivators, 379 cases (17.5%) by thrashing machines and 316 cases (14.6%) by reapers. The accidents caused by these three types of machines accounted for 1, 259 cases (58.1%).
5. In the overwhelmingly large portion of the cases of accidents, sequelae broke out in fingers. Thus, 89.6% of those who were involved in machine accidents suffered from sequelae in fingers.
6. There were 1, 939 cases of finger accidents, of which 1, 032 accidents were caused by machine belts and 441 by machine blades. The accidents caused by these two items accounted for 75.9%.
7. From the statistical analysis, it might be said that the correlation coefficients between the number of farm machines available in a given area and that of accidents are less significant for cultivators and reapers, and that the environmental and working conditions are just as important elements as the number of machines.