內政部於2002年實施「三歲以下兒童醫療補助計畫」，期望以減免部分負擔方式來降低就醫門檻，增加幼兒醫療利用。雖然此政策頗受好評，但在健保低部分負擔的前提下，額外減免部分負擔是否增加幼兒醫療利用，有待進一步商榷。由於北市率先於1995年針對3歲以下兒童減免部分負擔，並於1998年將對象擴及4-6歲兒童，這個補助政策的擴充，提供了一個機會瞭解減免部分負擔對幼兒醫療利用的影響。本文使用1997至2000年健保資料庫中6歲以下兒童的西醫門診資料，分析補助政策擴充至4-6歲兒童時，該年齡組幼兒門診次數是否增加。爲了控制估計的可能偏誤，本研究進一步以北縣同年齡兒童爲控制組，採用「差異中的差異」(difference in difference)法進行分析。實證結果顯示減免部分負擔平均增加兒童門診次數1.6次，佔全年醫療利用7.8%，所估計的價格彈性爲-0.08。此外，低所得家庭兒童的價格彈性較大。
In 2002, the Ministry of Interior started the ”Medical Care Subsidy Program for Children under 3” that aims to incrcase children's use of medical care through the co-payment exemption. Although this program is highly praised, its effect on the children's medical use is not clear due to the low co-payment policy of the Taiwan National Health Insurance system. Because a similar program was first implemented in Taipei in 1995, and subsequently expanded to children aged 4-6 in Oct 1998, this expansion provides an excellent opportunity to examine the effect of the co-payment exemption. Using data from the National Health Insurance Data between 1997 and 2000, we investigate the effect of the co-payment exemption on the use of outpatient services by children, aged 4-6 and registered in Taipei. To reduce the selection bias, the ”difference in difference” method is adopted using children of the same age cohort and registered in Taipei County as the comparison group. Our results show that on average the co-payment exemption increases the yearly outpatient use by 1.6 visits or 7.8 percent; the price elasticity is estimated to be approximately -0.08. Finally, the demand response is found to be larger for children from low-income families.