Econ Papers Daily / 期刊论文
乌干达杂交玉米种子的参考点与可负担性认知：禀赋与预期的证据
Reference Points and Affordability Perceptions of Hybrid Maize Seed in Uganda: Evidence on Endowment and Expectations
摘要
Despite demonstrated yield advantages, adoption of hybrid maize seed in Sub‐Saharan Africa remains low, raising questions about smallholders' perceptions of value and affordability. We examine whether farmers value hybrid maize seed differently depending on whether they already possess it or form expectations about likely prices or ownership, and how this affects willingness to pay (WTP) for a 1‐kg pack of seed in Uganda. We elicit WTP and willingness to accept (WTA) using Becker‐DeGroot‐Marschak auctions and measure ownership expectations with a multiple price list. The experiment tests three mechanisms: an endowment effect, by comparing WTP and WTA; price expectations, by randomly varying price probabilities; and ownership expectations, by varying the probability of keeping the seed for free. We find a strong endowment effect: farmers require substantially more money to give up seed they already possess than they are willing to pay to acquire the same seed, with WTA exceeding WTP by about 60%. The average WTP of UGX 4605 is well below the market price of UGX 8500. Loss aversion is associated with lower WTP and higher WTA, but these effects are small, imprecise, and do not explain the valuation gap. We do not find evidence that price expectations or ownership expectations generate economically meaningful reference points. Overall, our results indicate that current possession of seed is a more salient benchmark for valuation than forward‐looking expectations. These findings suggest that scaling strategies establishing early ownership, such as trial packs or plant‐now/pay‐after‐harvest schemes, may be more effective than attempts to shift price expectations alone.
中文摘要
尽管杂交玉米种子已显示出产量优势，但在撒哈拉以南非洲的采用率仍然较低，这引发了关于小农户对价值与可负担性认知的疑问。我们考察农民对杂交玉米种子的估值是否因其是否已拥有该种子、或对可能价格或所有权形成预期而有所不同，以及这如何影响其在乌干达对1公斤装种子的支付意愿（WTP）。我们使用Becker‐DeGroot‐Marschak拍卖引出支付意愿与接受意愿（WTA），并用多重价格列表测量所有权预期。实验检验三种机制：通过比较WTP与WTA检验禀赋效应；通过随机改变价格概率检验价格预期；通过改变免费保留种子的概率检验所有权预期。我们发现存在强烈的禀赋效应：农民放弃已拥有种子所要求的金额显著高于其获取同一种子所愿意支付的金额，WTA比WTP高出约60%。平均WTP为4605乌干达先令，远低于8500乌干达先令的市场价格。损失厌恶与较低的WTP和较高的WTA相关，但这些效应较小、不精确，且不能解释估值差距。我们未发现价格预期或所有权预期产生具有经济意义的参照点的证据。总体而言，我们的结果表明，当前对种子的占有是比前瞻性预期更显著的估值基准。这些发现表明，建立早期所有权的推广策略，如试用装或先种后付/收获后付款方案，可能比仅试图改变价格预期更为有效。