ارزش نهادن به منابع ژنتیکی در اقتصاد روستایی: مورد خوک بومی "بدون مو" در یوکاتان

We report the results of a choice-experiment study to model preferences over a selection of breed traits of ‘creole’ pigs. The study was conducted amongst households of backyard producers and small farmers rearing this local breed in Yucatan, Mexico. Hypothetical choice data were collected to estimate the preference of households over alternative pigs profiles whose attributes distinguish creole pigs from the potentially more productive, yet less adapted exotic breeds currently threatening to severely displace this locally adapted animal genetic resource (AnGR). The observed choices are employed to estimate a series of random utility models whose results are first tested for preference equality between households and small farmers, then endogenous segmentation is allowed within households by means of latent class models. Stated-preference based estimates are found to be of the same magnitude as revealed-preference producers costs. As a consequence the method is deemed to be appropriate for the valuation of non-market functions in production. Estimates conditional on household characteristics are then presented and discussed.

Most of the benefits produced by local livestock in marginal production systems are captured by producers, rather than consumers1. As a consequence the genetic resources of these breeds have mostly been shaped by producers’ preferences. It is, therefore, to the identification and characterisation of these preferences that research must turn to identify the implicit value of genetically determined traits as a first approximation to the valuation of local Animal Genetic Resources (AnGR). These breeds are often characterised by a bundle of genetically and phenotypically stable traits, which are often expressed in a complementary fashion. For example, foraging ability (selectivity of intake), tolerance of harsh ambient conditions, digestive capacity for fibrous diets, etc.

The premise of this applied study in valuation of AnGR for livestock production is that producers’ preferences guide the breeding process and hence determine the management of AnGR. Researchers, therefore, need adequate tools to characterise these preferences, bearing in mind that in peasant economies these are expressed only rarely in properly functioning markets. The relevance of pig-rearing as a means of food security and capital storage in Latin America, and the current threat of AnGR erosion faced by the indigenous creole pigs guided our choice of production system to rural Yucatan. A sample of 300 respondents across a set of 18 representative villages was surveyed and interviewed to administer a choice experiment investigating preferences regarding piglet costs, weight at 6 months, bathing frequency for heat relief, and disease resistance. All of these pig attributes are known to be in part genetically determined within the backyard production system and expressed differently in creole pigs and exotic imports.