Essays on collective participation in irrigated agriculture in Northern Mexico

The Coast of Hermosillo aquifer suffers from cones of depression and seawater intrusion because of excessive groundwater pumping over the years. Since irrigated agriculture consumes more than 92 percent of total groundwater resources extracted annually in the region (Conagua, 2009, 2015b), a study of factors influencing farming practices is central to designing any management plan that aims at ensuring the long-term sustainability of the aquifer. Further, achieving sustainable groundwater withdrawal levels requires effective collective involvement and management of the groundwater reservoir by the farming community. In the case of the Coast of Hermosillo, groundwater collectives have existed since the 1930s. However, several factors have contributed to farmers exiting the collectives, raising questions over the future sustainability of such institutions and also of the aquifer itself. From a policy perspective, it is paramount to understand the factors that weaken such institutional arrangements and the associated long-­term implications for groundwater health. It is also important to understand how alternative institutional designs can mitigate incentives for excessive groundwater extraction. Deriving a sustainable groundwater withdrawal plan requires coupling economic aspects of irrigation with the hydrological processes at a regional scale within an integrated framework. In case of Coast of Hermosillo aquifer, an integrated hydro-­‐economic analysis has been lacking. Using information from a survey that I conducted in the irrigation district of the Coast of Hermosillo, as well as statistics published by the Mexican Water Authority, I develop an integrated model that links the farmers’ need for profits maximization with the hydrological constraints in the Coast of Hermosillo aquifer. My thesis contributes to the above-­mentioned policy context in several ways. First, I develop an integrated hydro-­economic dynamic optimisation model that addresses how farmers’ crop choices can lead to the sustainable use of groundwater in Coast of Hermosillo, under a situation where both collective action and individual farming exist side by side. The hydrological model used here has several key characteristics. Specifically, it includes: an equation that calculates the depression cone, where multiple wells are pumping at different discharge rates; an equation that calculates the proportional change in groundwater storage in the collective action area resulting from a change in the groundwater storage in an individual action area; and a function that measures how the increase in the depression cone affects the salinity level resulting from seawater intrusion. Additionally, the model includes a function to identify reduction in crop yields in response to increasing root-zone salinity. Based upon several (collective and individually managed) scenarios constructed here, the results indicate that under the current rates of groundwater exploitation, the aquifer will get exhausted in a period of 25 years. When the government restricts annual water use to a maximum of the annual natural recharge in the aquifer, the groundwater lasts up to 100years, under both collective as well as private farming scenarios. The model results suggest that when farming is conducted under a collective arrangement, farmers derive higher overall utility, and the arrangement leads to conservation and maintenance of higher groundwater levels and limits salinity related damages to the aquifer. The originality of this approach, in comparison with other existing recent models are reviewed (Esteban & Dinar, 2012; Foster, Brozović, & Butler, 2015; Graveline, Majone, Duinen, & Ansink, 2013; Hurd & Coonrod, 2012; Josué Medellín-­Azuara et al., 2015; J. Medellín-­Azuara, Mendoza-­Espinosa, Lund, Harou, & Howitt, 2009; Josué Medellín-­Azuara, Mendoza-­Espinosa, Lund, & Howitt, 2008; Schwabe & Knapp, 2015; You & Ringler, 2010), resides in multiple characteristics: 1) This is the first integrated hydro-­economic model developed for the irrigated agriculture in Coast of Hermosillo, Mexico. 2) The model accounts for different institutional arrangements that compete in the use of groundwater on an aquifer threatened by overexploitation and seawater intrusion. 3) The model incorporates saline intrusion from an economic perspective, including a function to identify reduction in crop yields in response to increasing root-­zone salinity. 4) Asigmoid-­shaped function is calibrated to depict the proportional change in groundwater storage for a small area of the aquifer when there is a change in the rest of groundwater storage. 5) The model includes an empirical response function for salinity levels resulting from a decline in the water tables. 6) Finally, the model includes an empirical response function for number of farmers leaving the collective resulting from a proportional change (depletion) in groundwater level. Next, I test further econometrically for key determinants of collective stability. The empirical information shows, however, that the number of farmers exiting the collective arrangement has increased in the past decade. In order to explore the incentives for farmers’ decision-­making and the motives behind why farmers decide to exit early from the collective, I use multivariate probit analysis. The results indicate that the decision to make an early exit from the collective (within 5 years of joining the collective) is positively associated with shift towards high-­profit crops. Such early-­exiting farmers also tend to take a sustainable attitude regarding the aquifer. They support the creation of a sustainability fund and have up to date information about current groundwater water levels. Even though such farmers exit early, they prefer their children to continue in farming. A further analysis points to the fact that opportunistic farmers leave early, whereas those who have limited outside support tend to rely heavily on the collective and tend to stay within it for longer. Other variables such as depth of the water table, level of education, type of technology used in irrigation, social capital, and total net profits in farming, as well as a diverse set of individual attitudes and perceptions, also affect farmers’ decisionmaking with respect to exiting the collective. Finally, using duration analysis, I investigate the variables that influence the time span that farmers spend within the collective. The results from the duration model highlight a significant role played by idiosyncratic differences in various capital endowments (such as social, human, physical, financial and natural), as well as the diverse attitudes and perceptions of farmers in influencing their exit timings. Variables such as the relative influence of the collective arrangement on determining crop outcomes as compared to individual farming based crop outcomes outside the collective, conflicts associated with the decision-­making process within the collective and the perception of corruption within the government also tend to encourage farmers’ early exit. It is further found that the level of groundwater depletion and the associated risks of irreversible saline intrusion can also weaken the collective and prompt farmers to exit.