Comparison of four contingent valuation methods to estimate the economic value of a pneumococcal vaccine in Bangladesh
Comparison of four contingent valuation methods to estimate the economic value of a pneumococcal vaccine in Bangladesh
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DOI：
10.1017/s026646230808063x
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发表时间：
2008-09-01
影响因子：
3.2
通讯作者：
Bridges, John F. P.
中科院分区：
文献类型：
--
作者：
Heinzen, Rebekah R.;Bridges, John F. P.
目标：比较四种条件评估启发方法，作为估计孟加拉国肺炎球菌疫苗价值的方法，并测试这些启发方法是否存在偏差以及是否产生有效的响应。方法：在孟加拉国达卡招募了 361 个至少有一名 5 岁以下儿童的家庭。受试者被集群随机分配到各种诱导方法：开放式、二分选择（两个要价之一）、支付卡（具有不同范围的两张卡之一）。然后采用二分选择方法进行竞价游戏方法，以二分选择价格作为竞价游戏的起始价格。分析重点是汇总统计、需求曲线估计和多元回归分析，以检验有效性和偏差。结果：31 户拒绝参与，总共 330 户参与（答复率为 91.4%）。不同方法的支付意愿估算差异很大 (p < .001)，平均估算值在 2.34 美元到 18 美元之间变化。人们发现开放式启发法会产生高度夸大的值，而这些值对于构建有效性测试不敏感。二分选择法产生的是数量（需求）估计而不是价值估计，并且有一些证据表明是这样的。发现支付卡诱导方法受到范围偏差的影响。研究发现，竞价游戏启发法对起点偏差和赞同的敏感度较低。结论：不同的启发形式确实会产生不同的需求曲线；然而，这可能部分是由于他们没有衡量相同的结果。例如，二分选择形式产生需求曲线，而支付卡、开放式和竞价游戏则产生逆需求曲线。所有格式都容易出现多种偏差。选择启发格式时，首先考虑数据的目的和用途非常重要。每种启发方法都有其优点和缺点，并且可用于技术评估的不同目的。
Objectives: To compare four contingent valuation elicitation methods as a means to estimate the value of a pneumococcal vaccine in Bangladesh and to test if the elicitation methods are subject to bias and if they produce valid responses.Methods: Three hundred sixty-one households with at least one child under 5 years of age were recruited in Dhaka, Bangladesh. Subjects were cluster-randomized to various elicitation methods: open-ended, dichotomous choice (at one of two asking prices), payment card (one of two cards with differing ranges). The dichotomous choice method was then followed up with a bidding game methodology, with the dichotomous choice price acting as the starting price for the bidding game. Analysis focused on summary statistics, demand curve estimation and multivariate regression analysis to test for validity and bias.Results: Thirty-one households refused to participate, leaving a total of 330 participating households (a 91.4 percent response rate). Willingness to pay estimates varied significantly across the methods (p < .001), with average estimates varying between $2.34 and $18 (US). The open-ended elicitation method was found to produce highly inflated values that were insensitive to construct validity tests. The dichotomous choice method produced quantity (demand) estimates rather than value estimates, and there was some evidence of yea saying. The payment card elicitation method was found to be affected by range bias. The bidding game elicitation method was found to be less sensitive to starting point bias and yea-saying.Conclusions: Different elicitation format do give rise to different demand curves; however, this may be partially due to the fact that they do not measure the same outcome. For example, the dichotomous choice format produces a demand curve, while the payment card, open-ended and bidding game produce inverse demand curves. All formats are prone to multiple biases. When choosing an elicitation format, it is important to first consider the purpose and use of the data. Each elicitation method has strengths and weaknesses and can be used for different purposes in technology assessment.