Wildlife Conservation Research Unit, Department of Zoology, The Recanati-Kaplan Centre, University of Oxford, Oxford, United Kingdom.
PLoS One. 2011;6(7):e21243. doi: 10.1371/journal.pone.0021243. Epub 2011 Jul 20.
Farming of animals and plants has recently been considered not merely as a more efficient and plentiful supply of their products but also as a means of protecting wild populations from that trade. Amongst these nascent farming products might be listed bear bile. Bear bile has been exploited by traditional Chinese medicinalists for millennia. Since the 1980s consumers have had the options of: illegal wild gall bladders, bile extracted from caged live bears or the acid synthesised chemically. Despite these alternatives bears continue to be harvested from the wild. In this paper we use stated preference techniques using a random sample of the Chinese population to estimate demand functions for wild bear bile with and without competition from farmed bear bile. We find a willingness to pay considerably more for wild bear bile than farmed. Wild bear bile has low own price elasticity and cross price elasticity with farmed bear bile. The ability of farmed bear bile to reduce demand for wild bear bile is at best limited and, at prevailing prices, may be close to zero or have the opposite effect. The demand functions estimated suggest that the own price elasticity of wild bear bile is lower when competing with farmed bear bile than when it is the only option available. This means that the incumbent product may actually sell more items at a higher price when competing than when alone in the market. This finding may be of broader interest to behavioural economists as we argue that one explanation may be that as product choice increases price has less impact on decision making. For the wildlife farming debate this indicates that at some prices the introduction of farmed competition might increase the demand for the wild product.
最近，人们不仅将动植物养殖视为更高效、更丰富的产品供应方式，还将其视为保护野生种群免受贸易影响的手段。在这些新兴养殖产品中，可能包括熊胆。熊胆已被传统中药学家利用了数千年。自 20 世纪 80 年代以来，消费者有以下几种选择：非法野生胆囊、从笼中活熊提取的胆汁或化学合成的酸。尽管有这些替代品，熊仍继续从野外被捕获。在本文中，我们使用中国人口随机样本的陈述偏好技术来估计野生熊胆和养殖熊胆竞争时的需求函数。我们发现，人们对野生熊胆的支付意愿远高于养殖熊胆。野生熊胆的自有价格弹性和与养殖熊胆的交叉价格弹性都较低。养殖熊胆对野生熊胆需求的抑制作用充其量是有限的，并且在当前价格下，可能接近零，或者产生相反的效果。估计的需求函数表明，当与养殖熊胆竞争时，野生熊胆的自有价格弹性比只有养殖熊胆时更低。这意味着，当存在竞争产品时，现有产品的销售额可能会更高，即使价格更高。这一发现可能对行为经济学家更具广泛意义，因为我们认为，一种解释可能是，随着产品选择的增加，价格对决策的影响会降低。对于野生动物养殖辩论，这表明在某些价格下，引入养殖竞争可能会增加对野生产品的需求。
