Selected Papers

Woodill, A. J., Nakamoto, S. T., Kawabata, A. M., & Leung, P. (2017). To Spray or Not to Spray: A Decision Analysis of Coffee Berry Borer in Hawaii.

      Insects, 8(4), 116. [link]

Woodill, A. J., Hemachandra, D., Nakamoto, S. T., & Leung, P. (2014). The Economics of Coffee Production in Hawai’i, (June),1-9. [link]

Richardson, G. M., Bowers, J., Woodill, A. J., Barr, J. R., Gawron, J. M., & Levine, R. a. (2014). Topic Models: A Tutorial with R. International Journal

      of Semantic Computing, 08(01), 85-98. [link]

Working Papers

Nonlinear Temperature Effects and Short-Run Adaptation of the Dust Bowl Region during the 1930s

The Dust Bowl of the 1930s was one of the most significant environmental events in American history. Understanding the short-run adjustments from major weather events on agricultural yield can shed light on the economic impacts of changing weather conditions. Nonlinear temperature effects are examined in the Great Plains region of the US from 1910 - 1960 to identify changes in corn yield and short-run adaptation. Results show the Dust Bowl region had more harmful temperatures than the Northern Great Plains, but the temperature effect on corn yields were similar in each region; however, total corn yields from 1910-1960 were less in the Dust Bowl region. Nonlinear estimation results show slight adaptation in the Dust Bowl region and no adaptation in the Northern region. Adaptation appears to be limited in the short-run even with the introduction of hybrid corn and changing farming practices. Precipitation also appears to play less of a role on crop yields. These results add a historical perspective to the issue of short-run adaptation due to extreme weather events.

Optimal spraying and harvesting strategies to combat CBB in Hawaii: A dynamic approach

The arrival of the coffee berry borer (CBB) to Hawaii in 2010 has had a major impact on Hawaii coffee production. Many farms have shut down, processors are rejecting cherry with high levels of infestation, and farmers have had to adopt new farming practices, such as pesticide spraying, to reduce the damage done by this invasive species. To understand the optimal spraying and harvest strategies for a farm with CBB we first estimate the economic damages by modeling CBB infestation levels using a time-inhomogenous Markov chain. When a farmer decides to spray they reduce their infestation level, thus reducing economic damage but at a cost. We then develop a forward-recursion dynamic programming model to maximize the net benefit of a farmer to define the optimal spraying pattern and harvest strategy for a season. We plan to use our model to test strategies for different farm sizes based on integrated management practices, the impact of CBB infestation level changes from weather, and policy decisions, such as the impact of state-level subsidies.