Do people really even know what they want(ed)?

We examine the stability of preferences over time using panel data from Kenya on fertility intentions,realizations, and recall of intentions. We find that desired fertility is very unstable, but that most people perceive their desires to be stable. Under hypothetical scenarios, few expect their desired fertility to increase over time. Moreover, when asked to recall past intentions, most respondents report previously wanting exactly as many children as they desire today. Biased recall of preferences over a major life decision could have important implications for measuring excess fertility, the evolution of norms,and the perceived need for family planning programs.

That is from a new NBER working paper by Maximilian W. Mueller, Joan Hamory Hicks, Jennifer Johnson-Hanks, and Edward Miguel.