Investigating the Socioeconomic Determinants of Solar Pump Adoption Among Respondents in Bangladesh: A Firth’s Penalized Likelihood Logistic Regression Approach

This study examines the socioeconomic and behavioral determinants, together with spatial heterogeneity, influencing the adoption of solar irrigation pumps in Bangladesh. Five study regions of Bangladesh were sampled using stratified random sampling to collect 257 respondents, who were familiar with both solar and diesel pumps, to justify the energy transition, ensuring sample equity throughout the regions. Income inequality among respondents was assessed using the Lorenz curve, revealing that the bottom 50% of respondents only earned 20% of total income, while a Gini coefficient of 0.46 indicated moderate to high income disparity. To determine whether socioeconomic factors and spatial heterogeneity significantly influence adoption decisions, a Firth’s penalized likelihood logistic regression model was employed, complemented by predictive and average marginal effects for regional categories. The results identified that training, social influence, large household size and income are the prominent drivers for solar pump adoption. Based on the significant spatial heterogeneity, we further recorded a five-point Likert scale response to design region-wise policy recommendations for the fast diffusion of solar pumps. Financial incentives emerged as the most critical policy lever, with 89.10% of respondents expressing strong agreement and a mean score of 4.83. Overall, these findings highlight the central role of socioeconomic and spatial factors in shaping adoption behavior and suggest that policy interventions should prioritize targeted financial and technical support to promote the equitable and rapid diffusion of solar irrigation technologies.