The world is experiencing a "polycrisis" era defined by convergence of multiple, interconnected global challenges including climate change, armed conflict, forced displacement, pandemics, and economic instability (Lawrence et al., 2024). These overlapping crises disproportionately affect young children, whose early developmental years are critically sensitive to environmental, emotional, and educational conditions, with disruptions resulting in long-term cognitive, socio-emotional, and academic disadvantages (Black et al., 2017; Shonkoff et al., 2012). Early childhood learning outcomes are particularly vulnerable in this context. Over 43.3 million children have been forcibly displaced due to conflict and instability, many lacking access to foundational early learning opportunities, while climate-related shocks significantly impair early cognitive development and lifelong learning potential (UNESCO, 2024; UNICEF, 2024). The COVID-19 pandemic caused prolonged closures of early childhood education centers, leaving approximately 40 million children without access to pre-primary education during a critical developmental window (UNICEF, 2024). These disruptions have exposed and widened equity gaps in learning outcomes, particularly among children from marginalized communities, low-income households, and conflict-affected regions. While Sustainable Development Goal 4 emphasizes inclusive, equitable, and quality education for all, progress tracking mechanisms often fail to sufficiently capture disparities in early learning opportunities and developmental outcomes (United Nations, 2024). SDG Target 4.2, which calls for universal access to quality early childhood development and pre-primary education by 2030, remains significantly off track, especially in low- and middle-income countries (UNESCO, 2024). Equity measurement frameworks currently used by global monitoring institutions tend to overlook intersectional vulnerabilities such as disability, gender, displacement, and language barriers, with most monitoring systems relying on aggregate national indicators that mask within-country inequalities and fail to capture nuanced effects of compounded crises (Brossard et al., 2020; Engzell et al., 2021).

Despite growing recognition of early childhood as a cornerstone for lifelong learning and human development, research and policy responses have remained fragmented, reactive, and insufficiently data-driven, particularly in crisis-affected settings (Downer et al., 2018; Hartono et al., 2025). The lack of reliable, disaggregated, and context-sensitive indicators continues to obscure the full scope of inequities in early learning outcomes (Ancheta & Fabrigas, 2025). This study contributes to critical discourse by bridging the gap between global policy ambitions under SDG 4 and lived realities of young children in high-risk environments, offering an equity-centered critique of current monitoring approaches to inform more resilient, inclusive, and accountable early childhood education policies. The period from 2019 to 2023 presents a particularly critical window for analysis, encompassing both the disruption of the COVID-19 pandemic and subsequent recovery efforts that have tested the resilience and equity of early childhood education systems worldwide. OECD countries, while generally well-resourced and committed to comprehensive education data systems, present an important case study in tensions between policy commitments to inclusive education and practical realities of equity measurement. The availability of SDG 4 indicator data for these nations offers an opportunity to examine both what current monitoring systems reveal about early learning outcomes and what critical dimensions of equity remain obscured by aggregated reporting structures. Previous studies often fall short in capturing complex, systemic disruptions caused by global crises like the COVID-19 pandemic and emerging polycrisis, limiting their ability to inform how early education systems can sustain progress under such conditions. Moreover, many lack comprehensive, cross-national perspectives necessary to evaluate progress toward SDG 4 targets emphasizing inclusive and equitable quality education for all children. This study critically examines early childhood learning outcomes across thirty-eight OECD countries during this uniquely turbulent period (2019-2023), capturing both pre-pandemic baselines and multifaceted impacts of global crises on educational equity and system resilience. This broader, longitudinal, and international scope addresses significant gaps by assessing how early education systems withstand and adapt to overlapping crises, providing essential evidence for policymakers aiming to fulfill SDG 4 in an era marked by unprecedented challenges. This study analyzes SDG 4.1 indicators across thirty-eight OECD countries during the 2019-2023 period, with particular attention to early-grade proficiency levels in reading and mathematics that directly reflect quality and inclusiveness of early childhood education systems. By examining national-level achievement patterns, temporal trends through the pandemic era, and conspicuous absence of disaggregated equity data in standardized international reporting, this research contributes both empirical evidence and critical analysis to ongoing discussions about measuring progress toward truly inclusive early childhood education. The findings hold implications for researchers, policymakers, and practitioners working to strengthen rights-informed, equity-focused approaches to early learning across diverse national contexts.

The analysis of SDG 4 indicator data across thirty-eight OECD countries during the 2019-2023 period reveals significant variation in early-grade learning outcomes, temporal patterns reflecting pandemic impacts, and critical gaps in equity monitoring capacity. Results are organized according to the three research questions.

The findings reveal substantial variation in early childhood learning outcomes across OECD countries during unprecedented global disruption, with divergent pandemic trajectories and critical equity monitoring gaps illuminating both progress and persistent challenges in advancing toward Sustainable Development Goal 4.

The twenty-eight percentage point gap in reading proficiency demonstrates that national policy choices produce measurably different outcomes. Top-performing countries share common characteristics including substantial public investment exceeding one percent of GDP, near-universal pre-primary access, comprehensive teacher preparation, and robust social support structures mitigating child poverty, aligning with research emphasizing integrated policy approaches (Britto et al., 2017; Engle et al., 2011). However, aggregate national performance provides only partial insight into within-country equity. High proficiency rates suggest broadly inclusive systems but cannot reveal whether all children participate equally or whether certain groups remain systematically disadvantaged. This limitation reflects the critical data gap identified in Research Question 3, where aggregate indicators risk perpetuating epistemic violence by rendering marginalized populations invisible in accountability systems (Santos, 2014; Smith, 2012).

The temporal analysis reveals varying resilience to pandemic disruption. Highly resilient countries like Poland and Ireland maintained or improved performance despite widespread school closures through investments in digital infrastructure and family support systems enabling learning continuity (UNICEF, 2024). Conversely, Sweden's notable decline represents a reversal of strong performance, generating policy debate about support adequacy for immigrant and language minority children (UNESCO, 2024), while the United States' declining trajectory reflects longstanding challenges in providing equitable opportunities, with pandemic disruptions exposing and exacerbating pre-existing inequalities (Dorn et al., 2021). These patterns align with the polycrisis framework where overlapping challenges compound risks for vulnerable populations and strain systems' capacity to maintain quality and equity simultaneously (Lawrence et al., 2024).

Most critically, this study documents complete absence of disaggregated data across all equity dimensions in standardized international SDG 4 reporting. Despite explicit requirements for disaggregation by sex, wealth, and location, the dataset provides only national aggregates, representing fundamental failure to operationalize the "leave no one behind" principle (United Nations, 2024). The absence of sex-disaggregated data proves particularly puzzling given that gender breakdowns present minimal technical or privacy challenges. International assessments routinely collect such information, suggesting standardized international reporting mechanisms lag substantially behind national data collection capacity (Zhao et al., 2022). The invisibility of socioeconomic disparities, children with disabilities, immigrant and language minority children, and Indigenous populations means groups most vulnerable to exclusion remain completely invisible in international monitoring systems, limiting ability to design targeted interventions (Campbell Barr & Bogatić, 2017). The neoliberal measurement paradigm manifests clearly here, as emphasis on efficiency and standardized accountability produces monitoring systems privileging easily quantifiable aggregate outcomes over documenting how different groups experience education systems (Ball, 2012; Hastings, 2019).

This study examined early childhood learning outcomes across thirty-eight OECD countries during the 2019-2023 period, revealing substantial variation in early-grade proficiency, divergent pandemic trajectories, and critical equity monitoring gaps. The twenty-eight percentage point gap in reading proficiency underscores that national policy choices produce measurably different outcomes, with top-performing countries sharing characteristics including substantial public investment, near-universal pre-primary access, and strong social support structures. However, aggregate national performance provides only partial insight into equity, as high average outcomes may mask persistent disadvantages faced by marginalized populations whose experiences remain invisible without disaggregated data. Temporal analysis reveals that approximately one-quarter of countries improved proficiency despite pandemic disruption, half maintained stable performance, and one-quarter experienced declines persisting through 2023, suggesting certain structural features provide protective effects during crises. Most critically, this study documents complete absence of disaggregated data across all equity dimensions in standardized international SDG 4 reporting. Despite explicit requirements for disaggregation by sex, wealth, and location, current monitoring systems provide only national aggregates that obscure within-country inequalities. This gap represents fundamental failure to operationalize the "leave no one behind" principle. The invisibility of children with disabilities, immigrant and language minority children, Indigenous populations, and those from low-income families constitutes structural violence that denies these children recognition in accountability processes. Addressing these gaps requires substantial strengthening of international monitoring architecture with attention to critical perspectives questioning whose knowledge counts and how to balance standardization with cultural responsiveness. Participatory approaches engaging communities in defining relevant outcomes offer promise for developing inclusive monitoring frameworks that honor multiple epistemologies while maintaining accountability for children's rights. The polycrisis context adds urgency to these reform imperatives, as robust equity monitoring becomes essential for identifying where disruptions hit hardest and evaluating whether emergency responses protect vulnerable children or widen opportunity gaps. For the global early childhood education community working toward SDG 4, the findings demonstrate that universal high-quality early childhood education demands more than expanding aggregate access. It requires systematic attention to reaching marginalized populations, monitoring outcomes across multiple equity dimensions, and holding systems accountable for serving all children rather than privileging those easiest to reach.