Time-series analysis of trends in unemployment, income inequalities, and suicide mortality in Taiwan, 1959-2005

Study objectives: Labor market conditions and income distributions of a society are known to influence its population suicide rates. This study was conducted to examine the associations of unemployment, income inequalities, and suicide mortality in Taiwan during the period from 1959 to 2005. Methods: Mortality rates for suicide , unemployment rates, as well as indicators for income inequalities for the whole studied period were obtained from official statistics. Rates for long-term unemployment were also obtained, which were defined as being unemployed for more than 1 year and were available after 1996. Graphical approaches and time-series analysis were used to examine the associations of suicide mortality with unemployment rates and income inequalities. Results: During the whole studied period, increases in unemployment were strongly correlated with higher suicide mortality across all age groups and in both genders, with stronger associations found in men than in women. However, inconsistent associations were observed in the most recent decade – while the overall unemployment rates had declined, suicide mortality rates continued rising. Further refinement of analyses showed that in recent years, increases in long-term unemployment and worsening income inequalities were more strongly correlated with the rising trend in suicide mortality. Conclusions: Findings of this study suggested that long term unemployment and income inequalities outweighed general unemployment rate in determining suicide mortality rates in recent years. Future research is needed to understand the contextual complexity behind these associations. Keywords: suicide mortality, unemployment, long term unemployment, income inequalities, secular trend, Taiwan.