As a memorial lecture of the retirement of Graduate School of Economics, Kyoto University, I gave an essay on the past experience of my lecture about Health economics and Social Security and presented my view on Social Security in Japan. During past 20 years, I taught health economics and social security based on the way which behavioral economics suggests, as well as the orthodox principle of neoclassical economics suggests. In this essay, I picked up several topics on designing social security system. My emphasis is placed on the difference of difficulty of predicting future long-term economic growth and predicting the degree of technological progress in health care. As a final remark of this essay, I proposed the necessity of the research of these topics to relate recent development of economics of happiness.
