round. For instance, we may expect greater reporting bias for the year 1988 in the survey conducted in 2005-06 than in the survey conducted in 1992-93. Figure A.2 shows that the reported sex ratio at birth does not vary by survey round.

We also check if the fraction female among deceased children varies by recall period for deaths within one month of birth and for deaths within five years of birth for firstborn children, always restricting the sample to allow full exposure to the allowed window of death. Figures A.3 and A.4 suggest that there is no significant gendered recall bias.<sup>37</sup> We also previously showed in Table A.3 that the sex ratio of first births did not change over time as a function of maternal characteristics, including characteristics like education and religion that have been associated with son preference. If groups with high son preference are more likely to exhibit _gendered_ recall of deceased children, this result eases concern that recall bias drives our conclusions.

**Selection vs. changes in son preference.** As discussed in Section 1, availability of ultrasound scans led to an increase in abortion of female fetuses by parents who did not want a girl (and the data suggest that a greater proportion of such parents were those who, by a random act of nature, had already had a daughter at first birth). We have shown that the average girl who survives to birth is more likely to survive to age five in the post-ultrasound period. This is because she is born into a family that wants her; since families that do not want girls now tend to abort them. In this sense, the estimated effects on EFM arise from sex-selective abortion allowing selection, resulting in girls being increasingly born to parents who want them. We do not need to invoke a change in son preference. This is similar to discussions in the wider literature on abortion, which highlight that average outcomes for children improve when abortion is allowed because low-SES women are more likely to avail of abortion (Grossman and Joyce (1990b), Levine and Zimmerman (1996), Gruber et al. (1999)).<sup>38</sup>

Note that the estimated specifications allow for flexible trends in son preference insofar as they includes gender-specific birth year fixed effects. Son preference in India is centuries old and, while availability of ultrasound facilitated the exercise of son preference, there is no reason that it would change preferences. We, nevertheless, investigate this further—by controlling for preferences in different ways, and by modeling trends in preferences and allowing these to vary by firstborn sex.

We include controls for women’s self-reported preferences (ideal number of children and ideal fraction of sons of children) in specification (1) and we include interactions of the preference variables with the _Female_ and _Firstborn girl_ indicators. Even if stated preferences are often measured

> 37The reason we restrict the sample to firstborn children is that we know that the sex ratio of first birth has not exhibited a trend. For higher-order births, any differences in the sex ratio at birth for deceased children by recall period will not only capture gender-bias in recall of child death (which is what we want to measure), but also trends in actual EFM and trends in the sex ratio of birth.

> 38Note that in the mother fixed effects specification, differences in under-5 survival between pre- and postultrasound daughters are still driven by parents desiring the later born daughter (which they chose to have) more than the first (which they could not choose) on average.

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