However, the exact timing of the natural hazards and surveys matter in interpreting our empirical results, although we adopt the unique approach described in the previous sections. In Bangladesh, the initial survey round was fielded almost immediately after the 1998 flood. Though effects of the disaster were gradually realized after the flood, the initial round would already have captured some of the effects of flood exposure. The subsequent two rounds conducted within a year captured dynamic changes of the disaster’s impact. This issue is especially important in child anthropometry, if malnutrition led to child weight loss soon after the flood.<sup>11</sup> Therefore, the interpretation of the empirical results needs special attention. However, we think that child height is more robust than child weight to shocks.<sup>12</sup> For pre-flood assets, however, the data were constructed to reflect the pre-flood situation.

In contrast, the initial survey rounds in Ethiopia and Malawi took place before the 2001 droughts. Thus, the information on child schooling and anthropometry are not contaminated by the influence of the droughts (except the parts explained by ex-ante actions). However, potential problems arise from the interval between the 2001 droughts and the 2004 follow-up survey. Given that the actual impacts on income that are supposed to have occurred in 2001-2002, the interval between the drought and the 2004 survey was rather short. This means that we may not capture the recovery process of human capital investment in the two-year period.

Malawi had a large flood in 2001-2002 after the 2001 drought. However, our preliminary analysis indicates that the impacts of the flood were rather small, compared to the drought. Therefore, we focus on the 2001 drought in Malawi for the empirical analysis. The above concern on the interval between natural hazards and the follow-up survey also holds.

Differences in the time structure of the hazards and the initial and follow-up rounds change the way in which we interpret empirical results. In Bangladesh, first, we may underestimate the initial impacts on child human capital since the first round, immediately after the flood, already contained some of the most immediate impacts. However, this survey is ideal for capturing the recovery dynamics of human capital starting immediately after the flood. Second, in Ethiopia and Malawi, the setting is suitable to investigate the short-run impacts on human capital investment as the interval between the droughts and the follow-up survey was rather short.

Third, in Bangladesh, using the three rounds conducted in a year after the flood, we can reveal short-term changes of child anthropometry after the flood, though the initial round could include some of immediate adverse impacts of the flood. Overall, the Bangladesh setting provides both long-term and short-term dimensions.

The 2004 surveys conducted in all three countries have retrospective information on past disasters. This is useful for knowing the frequency of disasters that households experienced until 2004. The frequency is defined as the empirical average of incidences in the period from the initial to the last round. This preliminary work showed that Ethiopia and Malawi experienced several droughts between the initial and follow-up rounds. In Bangladesh, however, the 1998 flood was the single most devastating

> 11Similarly, grades completed were not affected at the initial round, but attendance rate (in term of days attended per the total number of school days) could be already changed after the flood.

> 12Child weight is sensitive to short-term morbidity, which is an issue in the case of floods. Water-borne diseases and diarrhea typically increase in the aftermath of a flood. In the analyses, we use the height-for-age z scores in the range of -6 to 6.

10