British economist and logician who codeveloped the marginal utility theory(published1886, which explains the value of goods and services in terms of the subjective valuation of consumers.

• 杰方兹，威廉 斯坦利1835－1882英国经济学家和逻辑学家。他与人合作发展了边际效益理论（1886年发表），该理论解释了根据消费者主观估价所产生的商品及服务的价值