The decrease in average household size in hotspot countries, they found, resulted in 155 million extra households between 1985 and 2000. (scientificamerican.com)
They calculated the population growth, number of households and average household size for 76 countries considered to include biodiversity hotspots (regions rich in endemic species that are threatened by human activity) and 65 that do not. (scientificamerican.com)
Over the 20th century, average household size declined reflecting increased incomes and demographic factors, notably a lower birth rate and an increase in the share of single adult households with or without children (Graph 2). (rba.gov.au)