Aims. To assess how income affects hypothetical drug and nan-drug purchasin
g decisions. Participants and setting. Ninety-four subjects (26 heroin abus
ers, 28 cocaine abusers, 15 alcohol abusers and 25 non-drug using controls)
were recruited from advertisements. Intervention. Subjects were exposed to
six conditions in which they "purchased" drugs as well as food, housing, a
nd entertainment as income rose from $30 to $560 per day. Findings. Heroin
abusers selected significantly more hypothetical heroin and cocaine as inco
me rose and demand for these two drugs was income elastic, with purchases r
ising in greater proportion than income. Cocaine abusers significantly incr
eased purchases of, and showed income elastic demand for, cocaine and alcoh
ol. Among alcohol abusers, significant increases in purchases and income el
astic demand mere found for alcohol and cigarettes, but not for other drugs
. Across all four groups, demand for rent and food were income inelastic, s
uch that purchases did nor rise in proportion to the changes in income, whi
le demand for entertainment was income elastic. Hypothetical choices were r
eliable between and within subjects, and drug choices were correlated with
urinalysis results and life-time years of drug use. Conclusions. Income is
an important variable in understanding choices for drug and non-drug commod
ities across a variety of substance-abusing populations.