Dynamics of variety change on wheat farms in Pakistan: A duration analysis

- We study factors affecting the lag between release and adoption of wheat varieties.
- We apply a duration model to identify differences in factors and lags by farm size.
- Education and extension reduce the adoption lag for small and medium-large farmers.
- Experience and information from social networks speed adoption for marginal farmers.
- Higher wheat seed prices lengthen the adoption lag for all farm sizes.

Decades after the Green Revolution, sustaining wheat productivity remains an important policy goal for the government of Pakistan. Understanding the speed of diffusion of new wheat varieties can contribute to this goal. We apply duration analysis to identify the factors that shorten the time until a farmer replaces one modern variety by another, and test hypotheses concerning two recurring themes of the Green Revolution: farm size differences and the role of information sources in seed diffusion. We find that time to adoption averages only 4 years, but is shorter on larger farms. Factors that speed variety change also differ by farm size. Extension and media sources of information significantly influence adoption among larger farmers relative to information gained through social relationships, but this is not the case for marginal farmers. Traits related to consumption quality speed adoption on smaller wheat farms, where families both sell and consume their wheat; higher yields drive adoption for the most subsistence-oriented, marginal group.