| Sumario: | This study used Box-Cox transformations to examine non-linearity in price modeling and compare results from several functional specifications in hedonic price analysis of yam in Togo. Based on a sample of 6402 observations on price and produce characteristics generated through a market experiment, it found that the Box Cox quadratic asymmetric specification is the most suitable function. Several characteristics were valued more than others, and prices varied across species, time, and market sites. Some residual symptoms of pest and disease damages on yam tubers discounted their market values. Tuber weight exhibited a diminishing marginal value and unit price decreased above an optimum size; therefore, producers did not derive additional reward from extra-large tubers. To effectively access and benefit from urban markets, producers should focus on small size, low weight, and conical shaped-tubers, which are easy to process and meet the esthetic qualities preferred by urban consumers. The implications for research on improved variety development to reduce poverty and for crop and resource management practices are drawn.
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