Nathan P. Hendricks

Crop Supply Dynamics and the Illusion of Partial Adjustment

We use field-level data to estimate the response of corn and soybean acreage to price shocks. Our sample contains more than 8 million observations derived from satellite imagery and includes every cultivated field in Iowa, Illinois, and Indiana. We estimate that aggregate crop acreage responds more to price shocks in the short run than in the long run, and we show theoretically how the benefits of crop rotation generate this response pattern. In essence, farmers who change crops due to a price shock have an incentive to switch back to the previous crop to capture the benefits of crop rotation. Our result contradicts the long-held belief that agricultural supply responds gradually to price shocks through partial adjustment. We would not have obtained this result had we used county-level panel data. Standard econometric methods applied to county-level data produce estimates consistent with partial adjustment. We show that this apparent partial adjustment is illusory, and we demonstrate how it arises from the fact that fields in the same county are more similar to each other than to fields in other counties. This result underscores the importance of using models with appropriate micro-foundations and cautions against inferring micro-level rigidities from inertia in aggregate panel data. Our preferred estimate of the own-price long-run elasticity of corn acreage is 0.29, and the cross-price elasticity is −0.22. The corresponding elasticities for soybean acreage are 0.26 and −0.33. Our estimated short-run elasticities are 37% larger than their long-run counterparts.

Groundwater economics: An object‐oriented foundation for integrated studies of irrigated agricultural systems

[1] An integrated foundation is presented to study the impacts of external forcings on irrigated agricultural systems. Individually, models are presented that simulate groundwater hydrogeology and econometric farm level crop choices and irrigated water use. The natural association between groundwater wells and agricultural parcels is employed to couple these models using geographic information science technology and open modeling interface protocols. This approach is used to study the collective action problem of the common pool. Three different policies (existing, regulation, and incentive based) are studied in the semiarid grasslands overlying the Ogallala Aquifer in the central United States. Results show that while regulation using the prior appropriation doctrine and incentives using a water buy-back program may each achieve the same level of water savings across the study region, each policy has a different impact on spatial patterns of groundwater declines and farm level economic activity. This represents the first time that groundwater and econometric models of irrigated agriculture have been integrated at the well-parcel level and provides methods for scientific investigation of this coupled natural-human system. Results are useful for science to inform decision making and public policy debate.

Transaction Costs in Payment for Environmental Service Contracts

Payment for environmental service contracts commonly require actions beyond adoption of a practice, such as undergoing specified enrollment procedures, granting consent to being monitored, and paying penalties for violations. These provisions are a bundle of attributes a landholder must accept with contract enrollment, leading to transaction costs in the contracting process. This article develops a principal-agent framework to study the links between these transaction costs and the well-known information asymmetries between the landholders and the government agency offering contracts. Using stated choice data collected from a sample of farmers, we estimate a mixed logit model to quantify the contribution of different contract attributes on contract willingness-to-accept (WTA). More stringent provisions in contracts were found to raise individual WTA by widely differing amounts across farmers, but the average effects imply that overall contract supply is sensitive to stringency. From a series of microsimulations based on the estimated model, we find that transaction costs create a significant drain on the cost-effectiveness of contracting from the agencys point of view, similar in magnitude to the inefficiency created by hidden information. Although stringent contractual terms raise program expenditures, they may be justified if they raise compliance rates enough to offset the added cost. We also simulate an implicit frontier to trace out the change in compliance needed to justify a given increase in stringency. For environmental benefits in the range of previous estimates, this analysis suggests that stringent terms would need to substantially raise compliance rates to be cost effective.

The Effects of Policy Expectations on Crop Supply, with an Application to Base Updating

We develop a dynamic model to assess the effects of policy expectations on crop supply and illustrate the approach with estimates of the effects of base updating in U.S. crop programs. For corn and soybeans in the Corn Belt, the effect of base updating is relatively small because relevant crop alternatives are subject to similar policies and the alternatives are substitutes in production. Increasing acreage of one program crop to capture future payments from base updating reduces future payments from the alternative crop. We also use our model to assess the effect of base updating on acreage response to prices.

Futures Prices in Supply Analysis: Are Instrumental Variables Necessary?

Crop yield shocks are partially predictable-high planting-time futures prices have tended to indicate that yield would be below trend. As a result, regressions of total caloric production on futures prices produce estimates of the supply elasticity that are biased downwards by up to 75%. Regressions of the worlds growing area on futures prices have a much smaller bias of about 20% because although yield shocks are partially predictable, this predictability has a relatively small effect on land allocation. We argue that the preferred method for estimating the crop supply elasticity is to use regressions of growing area on futures prices and to include the realized yield shock as a control variable. An alternative method for bias reduction is to use instrumental variables (IVs). We show that the marginal contribution of an IV to bias reduction is small-IVs are not necessary for futures prices in supply analysis.

Grouped coefficients to reduce bias in heterogeneous dynamic panel models with small T

We propose the grouped coefficients estimator to reduce bias in dynamic panels with small T that have a multilevel structure to the coefficient and factor loading heterogeneity. If groups are chosen such that the within-group heterogeneity is small, then the grouped coefficients estimator can lead to substantial bias reduction compared to pooled GMM dynamic panel estimators. We also propose using a Wald test that can be used to assess whether pooled estimators suffer from heterogeneity bias. We illustrate the usefulness of grouped coefficients with an application to labour demand in which the coefficients are grouped by sub-sector. Our results suggest that the standard pooled estimates are substantially biased.