Nowak, Eric Cosenza, Riccardo 2026 Carbon pricing exists in two forms whose economic properties differ more than the shared label suggests. Compliance markets such as the EU Emissions Trading System trade allowances whose existence and scarcity are administrative facts, whereas voluntary carbon credits are certified claims that emissions which would otherwise have occurred did not occur. Their defining property, additionality, cannot be observed, only estimated. This thesis argues that the voluntary carbon market is therefore a market in counterfactuals, in which the value of the traded unit depends on institutional credibility and quality credibility, and it examines this structure in three essays at three levels: international policy, corporate offsetting, and project measurement. The first essay studies four events around the Paris, Glasgow, and Dubai climate conferences using event studies and cointegration tests. Market participants price COP outcomes significantly and in both directions, and voluntary proxies build expectations more aggressively during negotiations and correct more sharply afterwards. The cointegrating relationship between compliance and voluntary markets disappears after Paris but persists around Glasgow, consistent with the Article 6 Rulebook resolving ambiguity over the recognition of voluntary units. The second essay links registry and equity data for listed firms and more than three thousand forestry credit retirements. Abnormal returns to retirements are indistinguishable from zero until the end of 2022 and significantly negative after a January 2023 media investigation into rainforest offsets. The effect is concentrated in credits without Climate, Community and Biodiversity certification, while certified retirements remain muted, providing the first evidence that investors value biodiversity co-benefits. The third essay re-examines the synthetic control study underlying that investigation. It shows that the misuse of global forest change pixel counts as area estimates, poorly constructed donor pools, and calculation errors each bias the estimates against finding project effectiveness, so the analysis cannot determine whether the projects deliver real carbon benefits. Taken together, the essays show that credibility is produced at the project level and consumed in prices: credible institutional resolution of quality ambiguity stabilizes valuations, its absence transmits shocks, and the price of environmental credibility ultimately depends on the reliability of applied econometrics. application/pdf https://susi.usi.ch/usi/documents/337549 https://n2t.net/ark:/12658/srd1337549 https://susi.usi.ch/documents/337549/files/2026ECO011.pdf eng info:eu-repo/semantics/altIdentifier/ark/12658/srd1337549 info:eu-repo/semantics/altIdentifier/urn/urn:nbn:ch:rero-006-124376 info:eu-repo/semantics/openAccess License undefined Carbon markets Voluntary carbon market EU Emissions Trading System Carbon offsets Climate policy Biodiversity finance REDD+ info:eu-repo/classification/udc/33 Essays in carbon markets http://purl.org/coar/resource_type/c_db06