[An analysis of the demand for influenza vaccination among the elderly in Japan]

This paper will discuss an analysis of the demand for vaccination for the elderly as a high-risk group. Influence of the governmental endorsement and/or subsidy on these demand is, then, evaluated from the estimation results.

Original data were obtained from two surveys conducted by the author for the elderly living with and without descendents. Information was collected about the elderly themselves, the household, experience of influenza and immunization in the last season, and the hypothetical questionnaire about immunization was answered by each respondent to be applied for Conjoint Analysis. Three estimations are performed for the actual behavior, Conjoint Analysis and the joint estimation of these two methods.

Experience of influenza and immunization in the last season, proved to be two of the most important determinants. Among the others estimated parameters, cost of immunization, the number of immunization to complete for effectiveness, availability of the immunization at night or on a weekend, and the governmental endorsement greatly affected the immunization demand. Moreover, the superiority of the statistical properties of the joint estimation was confirmed.

The estimation results imply that about 8.9 million elderly people would demand vaccination if there was no cost and there was a governmental endorsement. This would be reduced to be 3.2 million if the cost was 6,000 yen (about 50 dollars) and there was no governmental endorsement. Governmental endorsement alone would increase the number by 2.0 million. The change from no cost to only 500 yen (about 4 dollars) would depress the demand by 1.6 million.