利用价格激励来限制按需付费太阳能发电的福利

11374 Using Price Incentives to Bound Welfarefrom Pay-as-You-Go Solar Electricity Megan Lang Development EconomicsDevelopment Research GroupMay 2026 A verified reproducibility package for this paper isavailable athttp://reproducibility.worldbank.org,clickherefor direct access. Policy Research Working Paper11374 Abstract Non-price barriers suppress demand at the adoption margin,complicating efforts to quantify the welfare effects of ruralelectrification. This paper studies demand for pay-as-you-go(PAYGo) solar electricity using a randomized experimentwith 800 existing PAYGo customers in Kenya and Rwandapost-adoption. The experiment randomly assigns incen-tives that lower the effective price of usage for consumerswho meet monthly purchase thresholds. Although aver-age demand is unchanged, consumers with the highest pre-experimental demand increase their purchases by 6–7%in response to the incentive. These responses are used toestimate a lower bound on consumer surplus from PAYGosolar. The study finds large gains for high-demand consum-ers, but benefits deteriorate substantially for low-demandconsumers. Combining these estimates with evidence fromthe literature on the environmental externalities of solarhome systems, the marginal value of public funds of PAYGosolar subsidies is at most 1.7 in Kenya and 2 in Rwanda. This paper is a product of the Development Research Group, Development Economics. It is part of a larger effort by theWorld Bank to provide open access to its research and make a contribution to development policy discussions around theworld. Policy Research Working Papers are also posted on the Web at http://www.worldbank.org/prwp. The authors maybe contacted at mlang@worldbank.org. A verified reproducibility package for this paper is available athttp://reproducibility.worldbank.org, clickherefor direct access. The Policy Research Working Paper Series disseminates the findings of work in progress to encourage the exchange of ideas about developmentissues. An objective of the series is to get the findings out quickly, even if the presentations are less than fully polished. The papers carry thenames of the authors and should be cited accordingly. The findings, interpretations, and conclusions expressed in this paper are entirely thoseof the authors. They do not necessarily represent the views of the International Bank for Reconstruction and Development/World Bank andits affiliated organizations, or those of the Executive Directors of the World Bank or the governments they represent. UsingPriceIncentivestoBoundWelfarefromPay-as-You-GoSolar Electricity MeganLang∗ Keywords:Electricity access, welfare, solar. JEL Codes:D1, D6, H2, O2, Q4. 1Introduction Providing universal access to electricity requires electrifying increasingly remote and low-incomehouseholds. However, these households typically have low demand for electricity (e.g., Lee, Miguel,and Wolfram 2020, Grimm, Lenz, et al. 2020, Burgess et al. 2025). It is unclear whether this lowobserved demand for electricity accurately reflects the welfare consumers gain from electrification.For instance, credit constraints could bind for high upfront connection costs or appliance purchases,depressing demand even if consumers have a high value for electrification. Consumers may also faceuncertainty about low power quality and poor ongoing maintenance, or simply face bureaucratichurdles to connecting. All of these non-price factors shape observed demand, making it difficult toaccurately assess the welfare effects of rural electrification. Understanding the true value consumersplace on electricity is critical for determining whether the high costs of rural electrification are ajustifiable and efficient use of public resources. Pay as you go (PAYGo) solar home systems address many of the barriers that prevent householdsfrom adopting electricity.PAYGo contracts spread out payments over time.Consumers make asmall down payment to have a solar home system (SHS) installed, which includes solar panels andall of the basic appliances consumers can use with the system. Consumers pay off the system bypurchasing access time: time when they can use the electricity generated by the system. When aconsumer’s access time runs out, the solar company remotely locks them out of the system untilthey purchase more.Remote lockout provides a low-cost enforcement mechanism that enablesoff-grid companies to contract with rural, potentially low-income consumers.The contract alsoincludes after-sales service. Low population density in rural areas and limited demand among low-income households make basic solar home systems the least-cost option for many unelectrified areas(International Energy Agency 2017). Such systems do not incur the costs of expanding the grid andare sufficient to provide the limited energy services that many low-income households demand in theshort- to medium-term. Studying demand for electricity using the ongoing payments for PAYGosolar home systems