How Common Crop Yield Measures Misrepresent Productivity Among Smallholder Farmers

Abstract

Common estimates of agricultural productivity rely upon crude measures of crop yield, typically defined as the weight harvested of a crop divided by the area harvested. But this common yield measure poorly reflects performance among farm systems combining multiple crops in one area (e.g., intercropping), and also ignores the possibility that farmers might lose crop area between planting and harvest (e.g., partial crop failure). Drawing on detailed plot-level data from Tanzania’s National Panel Survey, our research contrasts measures of smallholder productivity using production per hectare harvested and production per hectare planted.

An initial analysis (Research Brief - Rice Productivity Measurement) looking at rice production finds that yield by area planted differs significantly from yield by area harvested, particularly for smaller farms and female-headed households. OLS regression further reveals different demographic and management-related drivers of variability in yield gains – and thus different implications for policy and development interventions – depending on the yield measurement used. Findings suggest a need to better specify “yield” to more effectively guide agricultural development efforts.

Initial results focusing on rice were presented by Leigh Anderson at the 2015 International Conference of Agricultural Economists in Milan, Italy.

Updated results from this paper for maize, rice, and sorghum were presented by Josh Merfeld at the 2016 Data for Policy Conference in Cambridge, UK, and are summarized in a conference discussion paper.

An updated paper building on this analysis and other previous EPAR research is currently under preparation for publication. This paper extends the analysis on productivity measures to rice, maize, and sorghum across three waves of data from the Tanzania National Panel Survey.