1. Introduction
The circular economy has emerged as one of the defining frameworks of contemporary economic policy, providing a systemic alternative to the linear take-make-dispose model of production and consumption that has underpinned industrial growth for more than two centuries. Its appeal rests on a compelling promise: that closing, slowing, and narrowing resource loops can simultaneously reduce environmental degradation and generate economic value, transforming waste into input, scarcity into opportunity, and cost into competitive advantage [
1,
2]. This promise has found its most ambitious institutional expression in the European Union, where the circular economy now constitutes a strategic pillar of the European Green Deal and the accompanying Circular Economy Action Plan [
3]. Through a dense architecture of regulatory instruments, from the Ecodesign Regulation and the Sustainable Products Strategy to the Critical Raw Materials Act and the revised Waste Framework Directive, the EU has signalled that circularity is no longer a voluntary aspiration but an increasingly binding condition of market participation across the Union’s single market.
Yet the realisation of this ambition depends, ultimately, on the behaviour of firms. And within the European enterprise landscape, it is small and medium-sized enterprises that occupy the most consequential position. SMEs account for approximately 99% of all enterprises in the European Union, generating a disproportionately large share of private sector employment and value-added relative to their individual size [
4]. Their collective engagement with circular economy principles is therefore not merely desirable but indispensable to any meaningful economy-wide transition toward circularity [
5]. At the same time, SMEs are structurally disadvantaged in their capacity to undertake this transition; they command fewer financial and human resources, operate with thinner margins, face more acute barriers in accessing information and technology, and exert weaker influence within supply chains than the large corporations that have attracted the bulk of CE-oriented research and policy attention [
6,
7].
Despite their central importance, the empirical literature on CE adoption among SMEs remains fragmented, geographically uneven, and marked by three persistent gaps that the present study addresses directly. The first gap concerns the determinants of CE adoption at the firm level. While existing research has identified individual drivers (financial resources, managerial commitment, regulatory pressure, and barrier perception), few studies have tested these factors jointly within a multivariate framework that controls for their mutual interdependencies and isolates their independent contributions [
8,
9]. The result is a literature rich in bivariate associations but poor in causal architecture; we know that investment, strategy, and barriers each correlate with CE adoption, but we know less about which dominates after controlling for the others, or whether their effects are contingent on one another.
The second gap concerns the relationship between national institutional context and firm-level CE behaviour. The overwhelming majority of empirical studies have been conducted within single countries or across narrow geographic samples, making it structurally impossible to identify the cross-national variation in CE adoption that is increasingly evident in aggregate data [
10,
11]. EU member states differ dramatically in their circular material use rates, from 1.3% in Romania to 32.7% in the Netherlands in the dataset, yet the implications of this heterogeneity for firm-level behaviour remain under-studied. Institutional theory suggests that such variation should matter, as firms embedded in more circular national ecosystems benefit from denser networks of secondary-material suppliers, stronger regulatory signals, and more conducive normative climates [
12,
13]. Testing this proposition requires a two-level (firm-and-country) design that combines firm-level data with country-level institutional indicators, a design that remains rare in the CE literature despite repeated calls for its adoption [
8,
13].
The third and most consequential gap concerns the economic returns on CE adoption. The narrative that circularity pays, that closing resource loops generates cost savings, opens new revenue streams, and enhances competitive position, is central to the business case for the circular transition [
14,
15]. Yet the empirical evidence for this relationship is considerably more mixed than the normative literature implies [
5,
16]. For SMEs specifically, the question is both theoretically open and practically urgent: if circular practices do not translate into measurable economic improvements within the horizons that matter to owner-managers and investors, the business case for voluntary adoption is fundamentally weakened, and the burden of the circular transition falls disproportionately on regulatory compulsion rather than market incentive. Providing rigorous, large-scale evidence on this relationship, rather than the small-sample case studies that dominate existing empirical work, is a direct contribution to the policy debate over how to design effective incentives for SME circular transition.
The present study addresses these three gaps through an original, two-level (firm-and-country) empirical analysis of 13,124 SMEs across all 27 EU member states, combining micro-level behavioural data from Flash Eurobarometer 549 (conducted in June 2024) with macro-level institutional indicators from Eurostat’s Circular Economy Monitoring Framework. We pursue three interrelated research objectives. First, we examine the firm-level and national-level determinants of CE practice adoption through hierarchical regression (Hypotheses H1–H5), identifying the relative contributions of investment, climate strategy, perceived barriers, firm size, and national circular material use rate. Second, we test whether CE adoption generates measurable economic returns, operationalised as self-assessed turnover evolution over three years, and whether these returns are contingent on sector and national context (Hypotheses H6–H8). Third, we develop an empirically grounded typology of European SMEs according to their behavioural profiles of CE adoption, using K-Means cluster analysis to identify latent groupings defined by the motivational basis of their circular engagement.
The study makes five contributions to the literature. It identifies an unexpected positive barrier adoption association, which we interpret tentatively as a commitment effect (H3 rejected), a pattern whereby firms further advanced in CE adoption report more barriers, because engagement with circularity generates the practical experience necessary to perceive obstacles that wholly passive firms cannot yet recognise. It decouples the effect of firm size from CE behaviour, demonstrating that the apparent size advantage disappears once investment and strategic commitment are controlled for, with significant implications for the design of public support programmes. It is among the first EU-27-wide quantitative assessments to document the absence of a direct, short-term relationship between CE adoption and economic performance, contextualising this result within the temporal and indirect nature of circularity-related benefits. It demonstrates a theoretically important asymmetry in the effects of national context; national circular maturity (CMUR) is positively associated with CE adoption (H5 partially supported) but does not amplify its economic returns (H8 rejected) and is in fact negatively associated with short-term performance, a finding that may reflect the compliance costs of advanced circular ecosystems and points to the need for a differentiated policy response. CMUR is a material-flow indicator rather than a policy or regulatory measure, so this association should be read as contextual rather than causal. Finally, it proposes a motivational profiling of CE adopters, Efficiency Investors, Strategic Green and Passive firms, introducing the dimension of adoption motivation as a primary axis of differentiation, less prominent in existing classifications, and situates these descriptive profiles within a geographic and sectoral analysis that reveals systematic institutional patterns across the Union.
The remainder of this paper is organised as follows.
Section 2 develops the theoretical framework and research hypotheses through a structured review of the relevant literature.
Section 3 describes the research design, data sources, variable operationalisation, and analytical methods.
Section 4 presents the empirical results across three analytical components: descriptive statistics, cluster typologies, and hierarchical regression models.
Section 5 discusses the theoretical contributions, practical implications for managers and policymakers, study limitations, and directions for future research, and
Section 6 concludes the paper.
5. Discussions
5.1. Theoretical Contributions
The results of the study make several theoretical contributions to the circular economy and sustainable innovation literature, relevant in the context of the special issue whose aim is to examine the link between sustainability, business models and economic performance.
The first contribution consists in an unexpected positive barrier-adoption association, which we interpret tentatively as a commitment effect (H3 rejected). The finding that the barrier index is the strongest positive predictor of CE adoption (β = 0.333,
p < 0.001) contradicts the linear barrier-inhibition model dominant in the previous literature [
8,
9] and suggests that the relationship is much more complex: barriers are not external and prior to adoption, but are endogenous to the circular transition process, perceived and articulated predominantly by active firms. Completely passive firms do not report barriers because they have not even initiated circular transition processes-they have not reached the awareness threshold necessary to identify obstacles. The theoretical implication is that models of CE adoption that treat barriers exclusively as inhibiting factors are incomplete; it is necessary to integrate the process perspective [
2], which recognises that commitment to CE itself generates awareness of difficulties. This reading remains tentative and post hoc: the cross-sectional design cannot establish the direction of the association, which is equally consistent with adoption preceding barrier awareness, and it requires confirmation through longitudinal evidence.
The second contribution aims to decouple the effect of firm size from CE behaviour. The rejection of H2 (β = 0.027, ns) in the hierarchical model, although the coefficient was significant in Block 1 before controlling for behavioural factors, suggests that the apparent effect of size is fully mediated by climate investment and strategy, not directly causal. This complements and nuances the literature supporting a direct effect of size [
5,
28]: in the context of the post-2020 European Green Deal, micro-enterprises with managerial commitment and access to resources can adopt CE practices as intensely as larger firms. The result sends an important message for public policies: interventions that exclusively target larger SMEs risk ignoring the significant potential of committed micro-enterprises.
The third contribution is conceptual and concerns the asymmetry of national-context effects between the two models. National circular material use (CMUR) is positively associated with CE adoption (Model 1, H5 partially supported, β = 0.108) but negatively with economic performance (Model 2, β = −0.064,
p < 0.001), without moderating the CE-performance relationship (H8 rejected). CMUR is a material-flow indicator (Eurostat cei_srm030), not a policy measure, so this asymmetry is read as associational rather than causal. This asymmetry introduces a new and relevant conceptual distinction: the national context is associated with CE behaviour, but not with the economic return on this behaviour. In other words, firms located in higher-CMUR contexts tend to do more, but do not appear to earn more from doing so, at least not in the short term. This nuance is missing from the existing literature, which tends to treat the national context either as a uniform facilitator [
13] or as an irrelevant factor (firm-level studies only).
The fourth contribution concerns the near-null association in H6, which constitutes one of the most important findings of the study. The absence of a substantive direct effect of CE practices on self-assessed economic performance (β = 0.025; statistically detectable at n > 12,000 but negligible, OR ≈ 1.06) provides robust evidence that the CE-financial performance relationship is not direct and immediate. The present study provides large-scale EU-27 evidence consistent with this conclusion.
The fifth contribution is taxonomic in nature and extends the understanding of the typologies of CE adoption. The coexistence of three descriptive profiles, efficiency-investors (13.7%), strategic-green (32.0%) and passive (54.3%), with different behavioural patterns suggests that the circular transition of European SMEs does not follow a single path. These profiles extend previous classifications of circular business models [
27] by introducing a behavioural dimension as a primary differentiating axis: internal commitment versus market response versus inaction. Furthermore, the geographical analysis suggests that the distribution of these profiles is not random, but is consistent with national institutional patterns, in line with institutional theory applied to organizational behaviour [
12].
5.2. Practical Implications
5.2.1. Managerial Implications
The confirmation of H1 and H4 highlights that the adoption of CE practices is essentially a strategic and investment decision, rather than an automatic effect of external pressures or firm size. Managers who formalise a commitment to sustainability, even at the level of a climate-strategy statement, independently adopt more CE practices, suggesting that the design of intention [
36] matters as much as the availability of financial resources.
The rejection of H2 sends a welcome message to entrepreneurs in micro-enterprises: small size is not a decisive obstacle to CE adoption. On the contrary, the agility and rapid adaptive capacity of small firms may constitute competitive advantages in the circular transition, particularly in a context where European funding programmes (structural funds, Horizon Europe, InvestEU) are becoming increasingly oriented towards sustainability.
The near-null H6 finding, the absence of a substantive short-term effect of CE on self-assessed economic performance, should not be interpreted as an argument against investing in circularity. On the contrary, managers should understand that the economic benefits of CE are likely to manifest chiefly through indirect and longer-term channels: reduced raw-material and energy costs, lower waste-disposal costs, greater resilience to supply shocks, and improved standing with customers and investors. These benefits are not immediately reflected in self-reported performance, but may contribute to financial soundness and competitiveness over the medium and long term.
The strategic-green profile carries an important practical message for managers in physical-product sectors. The at most partial and provisional support for H7, the positive effect of CE on performance in the industrial sector, suggests that industrial SMEs may have the most to gain from the systematic adoption of CE practices, probably because of the high potential for resource-cost reduction in material- and energy-intensive sectors.
5.2.2. Public Policy Implications
The size of the passive profile (54.3% of European SMEs) represents the most sobering message of the study from a public-policy perspective. More than half of EU SMEs adopt virtually no CE practices and have neither a green-market strategy nor a broader sustainability orientation. The geographical analysis shows that this profile dominates in 24 of the 27 member states, including large economies such as Germany, France, Italy and Poland, implying that the problem is not peripheral but systemic.
The partial support for H5, considered alongside the geographical cluster analysis, is consistent with the possibility that national circular-economy contexts are associated with individual firm behaviour beyond direct regulation. Member states with low CMUR, especially in Central and Eastern Europe (Romania: 1.3%, Bulgaria: 5.0%, Croatia: 5.9%), might prioritise not only recycling infrastructure but also enabling ecosystems for SMEs: access to green finance, industrial-symbiosis platforms, and resource-efficiency advisory programmes. The contrast with the Netherlands (CMUR = 32.7%) and Belgium (CMUR = 22.7%) illustrates the scale of the gap that policy may need to bridge: countries at the top of the circularity distribution have built dense networks of secondary-material markets and institutional support that are largely absent in lower-CMUR economies. Because CMUR is a material-flow indicator rather than a policy measure, these readings are associational and should not be interpreted as causal effects of specific national policies.
The negative association between ZCMUR and economic performance (H8 rejected; direct negative association β = −0.064, p < 0.001) raises an important policy question: might the more circular-mature national contexts be accompanied, in the short term, by a trade-off between systemic circularity maturity and the economic performance of SMEs? To the extent that such a tension exists, circular-transition policies could be accompanied by support mechanisms for SMEs that bear compliance costs without immediately benefiting from the competitive advantages of circularity. Programmes such as the Modernisation Fund or the Carbon Border Adjustment Mechanism (CBAM) could incorporate explicit SME-support components, not only measures for energy-intensive industries. The fact that several high-CMUR countries, including the Netherlands (32.7%), Belgium (22.7%) and France (17.8%), are nonetheless dominated by the passive profile despite advanced national circularity further suggests that aggregate material-use rates do not automatically translate into firm-level strategic engagement, pointing to the need for targeted, SME-specific instruments beyond infrastructure investment.
The tentative commitment-effect interpretation associated with H3, whereby perceived barriers are positively associated with CE adoption, suggests that CE support programmes might explicitly address the early stages of the transition. Firms that have not yet begun to explore CE practices are largely unaware of the barriers and are unlikely to benefit from interventions targeting obstacles they have not yet encountered. For firms in the strategic-green profile, more effective interventions might include awareness-raising and the demonstration of concrete benefits, visits to pilot firms, peer-to-peer mentoring between more and less advanced firms, and simple, transparent fiscal incentives for early investment in resource efficiency. The contrast between Austria (CMUR = 15.2%, dominated by the strategic-green profile) and Romania (CMUR = 1.3%, dominated by the passive profile) illustrates the dual challenge: both the institutional context and the firm-level behavioural baseline differ substantially, calling for differentiated policy approaches rather than uniform EU-wide instruments.
The at most partial and provisional support for H7, the positive effect of CE on performance in the industrial sector (β = 0.052, p = 0.022), provides a tentative, evidence-informed argument for differentiated sectoral policies. Industrial SMEs may represent a high-yield intervention priority: they appear to have the most to gain economically from CE adoption, yet not all have reached the adoption intensity of the efficiency-investors profile. Dedicated industrial-symbiosis programmes, eco-industrial parks and secondary-resource exchange platforms could accelerate the circular transition in this sector. More broadly, policy instruments that support green-product certification and consumer-facing sustainability communication could build on the existing market orientation of the strategic-green firms, deepening their strategic commitment while reinforcing their competitive positioning.
5.3. Study Limits
The present study presents several methodological and conceptual limitations that must be acknowledged. First, the cross-sectional design does not support robust causal inference: the relationships identified are statistical associations rather than evidence of causality. It is possible, for instance, that firms with high CE adoption subsequently become more aware of barriers (reverse causality for H3) rather than the reverse. This concern is particularly relevant for the tentative commitment-effect interpretation, which cannot be confirmed without temporal ordering. Testing directional causality would require panel data spanning multiple Eurobarometer waves (FL456/2017, FL498/2021, FL549/2024). A related concern is common-method bias: both the CE-adoption measures and the self-assessed performance measure derive from the same respondent and the same instrument, which may inflate observed associations; the negligible H6 estimate is, if anything, conservative in this respect. Second, measuring economic performance through self-reported turnover evolution is subjective and may be affected by social desirability or inaccurate respondent recall. The use of objective financial data from business registers or databases would strengthen the validity of Model 2 and allow testing of the effects of CE on profitability and cost efficiency, the dimensions most likely to be affected by circularity in the short term. Third, the sample is dominated by micro-enterprises: firms with 1–9 employees constitute 93.6% of the post-stratified (weighted) sample, although they represent 44.0% of the unweighted respondents. This weighting reflects the true prevalence of micro-enterprises in the EU-27 population, but it may limit the generalisability of the results to small and medium-sized firms, whose organizational structures and capacities differ considerably. Separate analysis by size category-micro, small, medium-could reveal heterogeneous effects of CE on economic performance that are masked by the predominance of micro-enterprises in the aggregate sample. Fourth, the CE-adoption index captures the breadth of practices adopted rather than validated circularity; it records how many distinct CE actions a firm reports, not the material or economic intensity of those actions, nor their verified environmental outcomes. Two firms with the same index score may therefore differ substantially in the depth of their circular transition. Results referring to CE adoption should be read with this measurement caveat in mind. Fifth, the CMUR variable captures only one dimension of the national CE context. Constructing a more comprehensive index of national CE maturity, integrating policy indicators (environmental taxes, regulatory intensity), infrastructure (separate-collection coverage), and organizational culture, would provide a fuller picture of the institutional context and might better explain the geographical variation observed in the cluster analysis. Sixth, patterns of missing data warrant careful interpretation, because part of the missingness is missing by design. Several barrier and investment items were reached only through questionnaire routing, so respondents who did not enter the relevant branch have no valid values on these items rather than genuinely absent responses. The listwise exclusion of 709 observations in Model 2 (5.4% of 13,124) is modest and unlikely to introduce substantial selection bias. A more relevant concern applies to the K-Means cluster analysis, where listwise exclusion reaches 23.3% (3061 cases), which may affect the representativeness of the identified profiles, particularly given the higher rate of missing values on the investment variable (q4: 18.0% missing after DK/NA were recoded as missing). A comparison of included and excluded cases shows that they are essentially indistinguishable in firm size, sector and national CMUR, but that excluded firms report lower CE adoption and fewer barriers, consistent with routing-driven missingness (the investment and barrier items are conditional on prior activity) rather than random attrition. This implies the sample means slightly overstate adoption while leaving the estimated associations robust, and it should be weighed when interpreting the passive profile in particular. Although multiple imputation is robust under the Missing At Random (MAR) assumption, a less restrictive condition than Missing Completely At Random (MCAR), a formal sensitivity analysis using multiple imputation would further strengthen the robustness of the cluster solution and its geographical interpretation. Seventh, the cluster solution itself is exploratory. The silhouette coefficient is modest and seed-stability only moderate, so the three groups are best understood as descriptive, reproducible profiles rather than statistically demonstrated types. Finally, the multilevel estimates for the national-context hypothesis (H5) rest on only 27 level-2 units (member states); with so few higher-level units, the precision of the country-level variance component and of the H5 coefficient is limited, which is consistent with the attenuation observed under multilevel estimation (p = 0.060) relative to the weighted OLS and country-clustered specifications.
5.4. Future Research Directions
The findings of this study open several fertile research directions that could advance the understanding of the relationship between sustainable innovation, circular business models and the economic performance of SMEs.
Longitudinal studies that follow the same firms across multiple Eurobarometer waves (FL456/2017, FL498/2021, FL549/2024) would allow directional causality to be tested and CE-adoption trajectories to be analysed over time, including the specific effects of European Green Deal policies. Such an approach could clarify whether the near-null short-term effect of CE on performance (H6 not substantively supported) resolves into a positive effect over a five- to ten-year horizon.
Investigating the mediation and moderation mechanisms in the CE-performance relationship is a priority. The effect of CE on performance may be mediated by intermediary variables such as product innovation, customer satisfaction or operational cost reduction, dimensions not captured by self-assessed performance. Testing these causal chains through structural equation modelling (SEM) would deepen the understanding of value-creation mechanisms in the circular economy.
Comparative research linking the identified descriptive profiles to long-term economic performance would address the central practical question: which of the three profiles, efficiency-investors, strategic-green or passive, is associated with the strongest financial results over three-, five- and ten-year horizons? Such research would require coupling FL549 data with objective financial records from databases such as Orbis (Bureau van Dijk) or Amadeus. Extending the analysis with objective financial-performance data, from commercial registers or Orbis/Amadeus-type databases, would substantially enrich the study of the CE-performance relationship and would allow the effects of CE on profitability, productivity and long-term survival to be tested, beyond self-assessed performance.
In-depth qualitative research on firms in the passive profile, which represents 54.3% of European SMEs, could clarify the nature of inertia towards CE: is it a lack of information, a lack of resources, an absence of external pressure, or a negative assessment of the cost-benefit ratio? Answering this question is essential for designing effective public policies to accelerate the circular transition among the majority of European SMEs.
Finally, comparative institutional analysis of the geographical patterns identified, with the strategic-green profile most prevalent in Austria, the Netherlands and Ireland, and comparatively strong in Sweden and Portugal, could, through in-depth case studies, identify the specific factors (political, cultural, infrastructural) that explain why these contexts have developed a relatively larger share of SMEs with a strategic orientation towards CE, and what lessons might be transferable to member states with low CMUR.
6. Conclusions
This paper set out to examine two complementary questions at the European Union level: what factors shape the adoption of circular-economy practices in SMEs, and whether the adoption of these practices is associated with economic performance. Drawing on a combined two-level database, Flash Eurobarometer 549 (13,124 SMEs across the EU-27) and Eurostat circular-economy indicators, and a hierarchical statistical methodology, the study provides nuanced and, in several respects, surprising answers to both questions.
Regarding the determinants of CE adoption (Model 1), the results indicate that the circular transition of SMEs is predominantly a strategic and deliberate phenomenon rather than an automatic consequence of firm size or external pressures. Investment in resource efficiency (H1 supported, β = 0.119) and the presence of a formalised climate strategy (H4 supported, β = 0.093) are significant predictors of CE adoption, independent of sector and national context. The national context, operationalised through the Circular Material Use Rate, is positively and significantly associated with CE adoption (H5 partially supported, β = 0.108; the association attenuates to p = 0.060 under multilevel estimation). Because CMUR is a material-flow indicator rather than a policy measure, this association is read as contextual rather than as evidence that specific national policies directly shape firm behaviour. Contrary to expectations, perceived barriers are positively associated with CE adoption (H3 rejected, opposite direction to the hypothesised effect, β = 0.333); we interpret this tentatively as a commitment effect, whereby firms already active in the circular transition are precisely those aware of and able to articulate the difficulties, while entirely passive firms report no barriers because they have not initiated transition processes. Firm size does not significantly predict CE adoption once behavioural factors are controlled for (H2 not supported), suggesting that micro-enterprises with managerial commitment can be as active in CE adoption as larger firms.
Regarding the effect of CE on economic performance (Model 2), the study identifies a telling absence: CE practices show no substantive association with self-assessed economic performance in the short term (H6 not substantively supported, β = 0.025, statistically significant at n ≈ 12,000 but negligible in magnitude, OR ≈ 1.06), and the national context does not moderate this relationship (H8 not supported, β = 0.003, ns). The only partial exception concerns the industrial sector, where CE adoption is positively associated with performance (H7 at most partially supported, provisional; β = 0.052, p = 0.022), suggesting that in material- and energy-intensive sectors, circularity may translate more readily into measurable economic advantages. These results do not refute the economic value of CE but contextualise it temporally and sectorally: the economic benefits of circularity are likely to manifest predominantly over longer horizons and through indirect channels-cost reduction, resilience to supply shocks, reputation-that are not captured by a short-term self-assessment of performance.
The exploratory K-Means analysis identifies three descriptive profiles of European SMEs: efficiency-investors (13.7%), characterised by high resource-efficiency investment; strategic-green firms (32.0%), combining an explicit climate strategy with green products; and a passive majority (54.3%) that is uniformly below average across CE dimensions. The coexistence of these three profiles suggests that there is no single path to the circular economy among SMEs. Their geographical distribution is consistent with an institutional pattern: only three member states, Austria, the Netherlands and Ireland, are dominated by the strategic-green profile, while 24 member states, including Romania, are dominated by the passive profile. This uneven distribution raises questions about the fairness of the circular transition across the EU and the case for differentiated policies across member states. Because the silhouette coefficient is modest and seed-stability only moderate, these profiles are best understood as descriptive and exploratory rather than as statistically demonstrated types.
The study has several limitations that must be acknowledged. The cross-sectional design does not support robust causal inference. Measuring performance through self-report introduces subjectivity and possible common-method bias. The predominance of micro-enterprises in the weighted sample (93.6%) may limit generalisability to small and medium-sized firms proper. These limitations point to clear directions for future research: multi-wave longitudinal studies, coupling with objective financial data (Orbis/Amadeus), and the investigation of mediation mechanisms through structural equation modelling.
The study contributes to the circular-economy literature through five elements: a tentative commitment-effect interpretation of the barrier-adoption association; the decoupling of firm size from CE behaviour; the identification of an asymmetry in national-context associations between adoption and performance; large-scale EU-27 evidence consistent with the absence of a direct, short-term CE-performance relationship; and a set of descriptive adoption profiles that extends existing classifications. Taken together, these contributions underscore that the circular transition of European SMEs is a complex, heterogeneous and deeply context-dependent phenomenon, organizational as well as national-institutional, that is unlikely to be understood or facilitated through a uniform approach.