Jan Jozwik‎ > ‎

Research Papers

 “Behavioural Factors and Technology Adoption: Experimental Evidence from Cocoa Farming in Ghana”

  (Job Market Paper)

This paper investigates the effect of trust and of an ambiguous environment on fertiliser investments under index insurance. These two behavioural factors were studied by means of a framed field experiment conducted with Ghanaian cocoa farmers. The subjects had an option to invest in a package of fertiliser bundled with index insurance with a positive level of basis risk. The returns depended both on the subjects´ investment choices and a stochastic weather realization. The key ingredient of the study was that for different subjects, the nature of the basis risk was framed differently. Substantially fewer subjects adopted fertiliser when possible losses of fertiliser investment were framed as resulting from the insurer´s failure to meet its contract obligations, compared with an alternative in which the losses were framed as resulting from a mismatch between their own weather realizations and those on which the index insurance was based. A large negative effect on fertiliser investments was also found in treatments with either a small or large ambiguity regarding the exact level of basis risk. Both negative treatment effects were strongly significant. This may suggest that technologies with which farmers are relatively more experienced are more likely to be adopted under index insurance schemes. The overall experimental findings provide evidence that trust and ambiguity may be significant factors other than basis risk, limiting the effectiveness of index insurance in promoting agricultural innovation.

 “Returns to New Technology and Comparative Advantage”


In this paper, I investigate whether returns to fertiliser in cocoa farming are high and whether farmers' adoption decisions can be explained by comparative advantage. I use data from Ghana to measure the returns to fertiliser by means of static and dynamic panel models of homogeneous returns to fertiliser, as well as a correlated random model of heterogeneous technology, which allows for farmer-specific comparative advantage. The estimated returns in different models are positive, high and strongly significant statistically. The effect of the comparative advantage on technology adoption decisions is found to be statistically significant. 

 “Gender Differences and Social Comparisons”

  (jointly with Michalis Drouvelis, Birmingham University, and Donhatai Harris, Oxford University)

Social comparisons are ubiquitous across many domains of economic and social life, affecting individuals’ judgements and attitudes towards others. In this paper, we examine the interplay between gender and social comparisons in individuals’ earned income (from a real effort task) and cooperative behaviour in a one-shot social dilemma game. Our main findings indicate that the effects of social comparisons are gender sensitive: women are more responsive to social comparisons. We find that women are significantly more likely to increase their earned income when social comparisons are present compared to men. However, when we allow for social comparisons women become less pro-social. We discuss potential mechanisms for the observed effects. Overall, our findings shed new light on the heterogeneous effects of social comparisons that may have important implications for institutional design based on social information.