Educational Inequality in the Digital Era: Distributional and Spatial Analysis of Thailand's O-NET

Abstract

Educational inequality in the digital era constitutes a critical challenge affecting human capital development and national competitiveness, particularly amid the transition to a digital economy and post-COVID-19 recovery.  While prior research has examined the effects of  socioeconomic factors on educational achievement, three significant gaps remain: (1) most analyses rely on mean-based approaches that fail to capture heterogeneity across the achievement distribution, (2) the role of digital access has not been systematically examined, and (3) spatial dimensions have received insufficient attention.  This study employs quantile
regression and spatial analysis using O-NET data from 49,639 Grade 9 students across 77 provinces in Thailand.  The analysis examines effects at the 25th, 50th, and 75th quantiles to investigate heterogeneity across achievement levels.  The spatial analysis focuses on explaining contextual differences between regions (spatial heterogeneity) rather than testing direct spatial dependence.   The results reveal severe inequality across three dimensions. First, the effect of the SES index increases from 3.40 points among low achievers to 15.50 points among high achievers (a 4.5-fold increase), reflecting cumulative advantage mechanisms whereby students from wealthier households have greater access to high-quality resources. Second, poverty exerts the strongest negative impact on low achievers (reducing scores by 0.30 points), indicating overlapping disadvantages among vulnerable groups.  Third, the achievement gap between Bangkok and other regions reaches 33.71 points, accompanied by significant spatial interaction effects, demonstrating structural inequality across geographic areas. The findings underscore the necessity of differentiated policy interventions: (1) poverty mitigation programs for low-performing students, (2) universal support mechanisms for middle-performing groups, and (3) capability enhancement policies for high-performing students, alongside regionally targeted investment to reduce inter-regional disparities. This study provides empirical evidence supporting equitable and sustainable education policies in the era of digital transformation.