Could the Debate Be Over? Errors in Farmer-Reported Production and Their Implications for the Inverse Scale-Productivity Relationship in Uganda

76 Pages Posted: 13 Sep 2017 Last revised: 21 May 2020

See all articles by Sydney Gourlay

Sydney Gourlay

World Bank - Development Data Group

Talip Kilic

World Bank - Development Data Group (DECDG)

David Lobell

Stanford University

Date Written: September 12, 2017

Abstract

Based on a two-round household panel survey conducted in Eastern Uganda, this study shows that the analysis of the inverse scale-productivity relationship is highly sensitive to how plot-level maize production, hence yield (production divided by GPS-based plot area), is measured. Although farmer-reported production-based plot-level maize yield regressions consistently lend support to the inverse scale-productivity relationship, the comparable regressions estimated with maize yields based on sub-plot crop cutting, full-plot crop cutting, and remote sensing point toward constant returns to scale, at the mean as well as throughout the distributions of objective measures of maize yield. In deriving the much-debated coefficient for GPS-based plot area, the maize yield regressions control for objective measures of soil fertility, maize genetic heterogeneity, and edge effects at the plot level; a rich set of plot, household, and plot manager attributes; as well as time-invariant household- and parcel-level unobserved heterogeneity in select specifications that exploit the panel nature of the data. The core finding is driven by persistent overestimation of farmer-reported maize production and yield vis-?-vis their crop cutting?based counterparts, particularly in the lower half of the plot area distribution. Although the results contribute to a larger, and renewed, body of literature questioning the inverse scale-productivity relationship based on omitted explanatory variables or alternative formulations of the agricultural productivity measure, the paper is among the first documenting how the inverse relationship could be a statistical artifact, driven by errors in farmer-reported survey data on crop production.

Keywords: Food Security, Crops and Crop Management Systems, Climate Change and Agriculture, Inequality, Nutrition, Coastal and Marine Resources, Forestry, Energy and Natural Resources, Forests and Forestry

Suggested Citation

Gourlay, Sydney and Kilic, Talip and Lobell, David, Could the Debate Be Over? Errors in Farmer-Reported Production and Their Implications for the Inverse Scale-Productivity Relationship in Uganda (September 12, 2017). World Bank Policy Research Working Paper No. 8192, Available at SSRN: https://ssrn.com/abstract=3036194

Sydney Gourlay (Contact Author)

World Bank - Development Data Group ( email )

1818 H Street, NW
Washington, DC 20433
United States

Talip Kilic

World Bank - Development Data Group (DECDG) ( email )

Via Labicana 110
Rome, Lazio 00184
Italy

David Lobell

Stanford University ( email )

Stanford, CA 94305
United States

Here is the Coronavirus
related research on SSRN

Paper statistics

Downloads
46
Abstract Views
274
PlumX Metrics