模仿和创新的传播

Imitation and the diffusionof innovation by Debi Prasad Mohapatra and Vatsala Shreeti Monetary and Economic Department April 2026 JEL classification: L13, O33, O34, L63Keywords: innovation, patenting, telecom, preferencediscovery BISWorking Papers are written by members of the Monetary and EconomicDepartment of the Bank for International Settlements, and from time to time by othereconomists, and are published by the Bank. The papers are on subjects of topicalinterest and are technical in character. The views expressed in this publication arethose of the authors and do not necessarily reflect the views of the BIS or its membercentral banks. This publication is available on the BIS website (www.bis.org). Imitation and the diffusion of innovation Debi Prasad Mohapatra∗Vatsala Shreeti† April 22, 2026 Abstract Why would a market leader choose not to patent an innovation?We studySamsung’s decision to forgo patent protection for dual SIM technology in the In-dian mobile handset market. Using a structural model of demand and supply es-timated on quarterly product-level data from the Indian mobile handset industry,we document that rival firms’ dual SIM products generated apreference discoveryexternality. Rival firms’ widespread adoption of the dual SIM technology allowedconsumers to discover the value of the technology, also benefiting Samsung itself.Counterfactual simulations show that a patent would have suppressed this exter-nality, reducing Samsung’s equilibrium profits despite holding monopoly rights.Voluntary non-patenting was therefore privately optimal. Our findings shed lighton wider debates about open-sourcing in software and other markets. Keywords:innovation, patenting, telecom, preference discovery JEL codes: L13, O33, O34, L63 1Introduction When a firm develops a new technology, it must decide whether to protect it from ri-vals or allow it to diffuse freely through the market.This decision is central to manycontemporary debates in technology policy and industrial organization. The rise of open-source artificial intelligence models, such as Meta’s LLaMA, alongside proprietary alter-natives like OpenAI’s GPT series, has reignited longstanding debates about the strategicvalue of openness versus protection (Arrow, 1962; Scotchmer, 1991; Boldrin and Levine,2008). Similar tensions arise in pharmaceuticals, where firms choose between patentingand allowing generic entry (Williams, 2013; Chaudhuri et al., 2006), in software, whereopen-source and proprietary licenses coexist (Lerner and Tirole, 2002) and in standard-setting, where firms may voluntarily share essential patents (Shapiro, 2000). Despite itsprevalence, the question of when and why it can beprofitablefor an innovator to forgoprotection of its innovation remains empirically underexplored. In this paper, we propose and quantify a mechanism—preference discovery—that canrationalize an innovator’s decision to allow imitation by its competitors. The core idea isthat when competitors adopt a new technology, they introduce it to consumer segmentsand price points that the innovator may not serve directly. This expanded product varietygenerates information about the technology’s value:consumers who would never haveencountered the innovation through the innovator alone learn about it through imitators’products. Willingness to pay for the innovation increases as a result, ultimately expandingthe market in ways that benefit the innovator. Preference discovery is distinct from, andcomplementary to, other explanations for tolerating imitation, such as costly enforcement(Lanjouw and Schankerman, 2001), network effects (Katz and Shapiro, 1985), or deterringentry into adjacent markets (Gallini, 1984). We study this mechanism empirically in the context of the Indian mobile handset mar-ket, focusing on the introduction of dual subscriber identity module (SIM) functionality—a product feature that allows consumers to use two different telecommunications oper-ators on a single device.Samsung introduced the first dual SIM handset in India in2007.Shortly after, dozens of competing firms, including small Indian brands with no R&D capability, rapidly adopted the feature with no intellectual property disputes. By2016, 44 out of 46 companies in the Indian market offered dual-SIM phones, and thesedevices accounted for 94% of handset sales by volume. Despite holding patents relatedto dual-SIM technology, Samsung chose not to enforce them, a decision that our analysisrationalizes through the preference discovery mechanism. This setting is well-suited for studying the role of preference discovery and marketexpansion following an innovation for several reasons.First, dual SIM technology is adiscrete, observable product characteristic, which makes it straightforward to track adop-tion across firms and time. Second, the market features a large number of heterogeneousfirms, ranging from multinationals with substantial R&D to local brands that began asresellers of unbr