Do income and capital influence household solar panel investment? A meta-regression

There is considerable variation in research explaining household solar-panel investment, leading to mixed evidence regarding influences of income and capital. We provide analysis aiding interpretation of economic influences on solar-panel uptake in other studies. We conduct a meta-regression using 234 papers to provide analytical insights focusing on economic influences on solar-panel investment. We find that the research approach and context explain a range of income influences. More specifically, studies using household-level data are less likely to find negative income impacts compared to studies using aggregate data. Developing-country studies have been less likely to include income; but when income is included, developing-country studies have been more likely to find a significant link from income to solar-panel uptake. Capital (e.g., asset) impacts are nearly always positive and significant when included, but only 22 percent of analyzed studies included a relevant variable. Our concluding policy discussion suggests greater focus on assets for means testing.