This research examines how pregnant women's self-selection affects the estimation of the infant health production function. A particular emphasis is placed on assessing the effectiveness of prenatal care as a major medical input in the birth-weight production function. The probability function of a pregnant woman's giving birth and the demand for prenatal care are also estimated. Primary data were compiled from a national survey on knowledge of, attitudes toward, and practice of family planning and reproductive health among married women in Taiwan. The results showed that the decision to give birth was significantly correlated with age, education level, and previous induced abortions. In addition, respondent' health behavior during pregnancy showed significant effects on infant birth outcome. Prenatal care was not found to have a significant effect on birth outcome. We also found that effectiveness of prenatal care tends to be biased downward when selection effects were not considered.
