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We leverage the largest polio outbreak in US history, the 1916 polio epidemic, to study how epidemic-related school interruptions affect educational attainment. Using polio morbidity as a proxy for epidemic exposure, we find that children aged 10 and under, and school-aged children of legal working age with greater exposure to the epidemic experienced reduced educational attainment compared to their slightly older peers. These reductions in observed educational attainment persist even after accounting for the influenza epidemic of 1918.

Starting in the 1930s, commercial hybrid corn seeds rapidly replaced the once predominant open-pollinated varieties planted by farmers. By the mid-1950s almost all corn grown in the United States was of hybrid varieties. Observers have argued that the drought-tolerant qualities of these hybrids were a major factor driving farmers' decisions regarding hybrid adoption, but there is little statistical evidence to substantiate this assertion. Hybrid seeds exhibited other attractive qualities, such as improved performance during prime weather conditions, resistance to wind damage, and increased suitability toward mechanized harvesting. Using historical evidence from Zvi Griliches's archival records, we reconstruct data on hybrid corn adoption and yields at a more disaggregated geographic level than previously available. We match these data with historical weather records to measure the extent to which hybrid seeds mediated the adverse effects of drought and extreme heat. Our findings suggest that hybrid corns grown in Iowa from 1928 to 1942 did exhibit both drought and heat tolerance relative to open-pollinated varieties. This result is unique to Iowa in the 1930s. The reduced temperature sensitivity does not appear when comparing yields of hybrid and open-pollinated corns grown in other states at other times.

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Diatoms are a common type of phytoplankton characterized by their silica exoskeleton known as a frustule. The diatom frustule is composed of two valves and a series of connecting girdle bands. Each diatom species has a unique frustule shape and valves in particular species display an intricate pattern of pores resembling a photonic crystal structure. We used several numerical techniques to analyze the periodic and quasi-periodic valve pore-network structure in diatoms of the Coscinodiscophyceae order. We quantitatively identify defect locations and pore spacing in the valve and use this information to better understand the optical and biological properties of the diatom.