Int. J. Environ. Res. Public Health 2010, 7 1906 quantity of consumption is not fully determined by tax-effect, as mothers’ demographic characteristics also have an effect. Given the low incidence of binge drinking (1%), I have run linear probability and logit models as well. Results from these two estimations are similar to the Probit model presented here, except that clustered standard errors are a little different. Table 2. Alcohol Taxes and Drinking while pregnant (BRFSS). # Drinks last month (2) Binge drinks (0/1) (3) # Drinks last month (5) Binge drinks (0/1) (6) Variables A. Coefficients Beer tax Wine tax Liquor tax Drink (0/1) (1) −0.003 (0.006) −0.001 (0.002) −0.0003 (0.001) B. Elasticity (Absolute Value) Beer tax 0.238 Wine tax 0.127 Liquor tax 0.147 Covariates no −0.2338 (0.247) −0.1133* (0.092) −0.0151 (0.026) 1.244 1.284 1.82 no −0.164 (0.243) −0.097 (0.089) −0.0109 (0.023) 0.875 1.098 1.319 yes −0.031** (0.016) −0.016*** (0.005) −0.006*** (0.002) 2.462 2.661 10.406 yes Drink (0/1) (4) −0.004 (0.006) −0.002 (0.002) 0.0002 (0.001) 0.329 0.317 0.419 yes −0.033*** (0.018) −0.015*** (0.007) −0.005*** (0.002) 2.499 2.493 8.975 no Beer tax Wine tax Liquor tax Sample size 17,242 15,945 11,411 Data come from the BRFSS (1985–2002). Even years between 1994 and 2000 were dropped because of its lack of national representative. Models in Columns 4–6 include covariates such as mothers’ age, age square, educational attainments, race/ethnic group, marital status and real income per capita. All taxes and prices are in cents and adjusted to CPI 1982–1984. In all models, state- and year-fixed effects are included. Marginal effects are reported with state-year clustered errors underneath in the parentheses. *** significance at 1% level, ** significance at 5% level, and * significant at 10% level. The sample sizes are as following: Price elasticity of demand measures the responsiveness of the quantity demanded of a good or service to a change in its price. Following Evans and Ringel [29], tax elasticity of demand changes on drinking participation is: . Specifically for this paper, where and are average level of taxes and average probability of drinking while pregnant. Table 2 also presents the tax-induced elasticities of alcohol demand. Per any 1% increase in taxes, the drinking prevalence decreases by 0.1–0.2%, indicating that drinking participation is irresponsive to prices induced by taxes among pregnant women. With the same amount of changes in taxes, the quantity of alcohol consumption decreases by 1.2–1.8%, meaning that quantity of demand is sensitive to alcohol taxes. It is not surprising that the quantity elasticities are larger than participation elasticities, as theory predicts