EVERY three years the National Institute of Alcohol Abuse and Alcoholism sends a special report to Congress on alcohol and health. John Mullahy, an economist at Trinity College in Hartford, Conn., has written on the economic side of the problem for the report, due out next year. In an interview, Mr. Mullahy summarized the research of dozens of economists showing that the abuse of alcohol does enormous damage to drinkers and thus the nation's economy. Here are the results from a rapidly growing body of research: * Youths who drink too much in general attain less schooling. For example, high school seniors who engage in frequent drinking complete 2.3 fewer years of college on average when compared with similar individuals who are not frequent drinkers. Those with less education, generally earn less as adults. * Men and women with a drinking problem are less likely to be married. * Problem drinkers are 10 to 15 percent less likely to be employed than nonalcoholics. They are 4 to 10 percent more likely to be unemployed and seeking work. ''Any drinking problem is an impediment to employment,'' says Professor Mullahy, who with Jody Sindelar of the Yale School of Public Health, New Haven, Conn., did this research. ''That may be no surprise.'' * Alcoholism and alcohol abuse reduce the earnings of men by as much as 26 percent. The loss for heavy drinkers can reach 11 percent. The loss of income for women appears less severe. * Moderate drinkers, up to one drink per day, often earn more than those who drink even less. But income starts slipping when the amount of alcohol exceeds that modest level. * Households that do not include an alcohol-abusing male have a 22.5 percent higher average income than households where an alcohol-abusing male resides. Further research has looked at what would be the effect of measures to curb the consumption of alcohol. For example, if the liquor industry could not deduct the cost of advertising from its taxable income, the resulting reduction in advertising would cut highway fatalities by about 1,300 per year in the United States. If beer and wine broadcast advertising were banned, between 2,000 and 3,000 lives would be saved. Another study, Mullahy notes, compared advertising practices for alcoholic drinks in 17 industrial nations, taking account of factors including price, income, sentiments toward drinking, and tourism. It found that in countries that banned the advertising of spirits, the consumption of ethanol (the alcohol in drinks) was 84 percent of the amount in countries without such a ban. If beer and wine advertising is also banned, ethanol consumption is about 89 percent of the level in those countries in which spirits ads are banned. Moreover, ad bans for spirits reduced motor-vehicle fatalities by about 10 percent compared with no-ban nations. In the case of bans on beer and wine ads, the drop in auto fatalities reached 23 percent compared with countries that ban only spirits ads. If states have higher taxes on beer, it decreases both alcohol consumption and the number of motor-vehicle fatalities in that state, according to yet another study. The same happens when the minimum legal drinking age is raised. One more study found that higher prices and taxes on alcoholic beverages reduced the amount of drunk driving. Another indicated that the more alcohol per capita is consumed in a state, the more rape, assault, and robbery increased. And higher beer taxes in a state were associated with lower crime rates. The consumption of alcoholic beverages is sensitive to higher prices, especially for those who are not alcoholics. In a state with higher beer taxes, the number of drinks per week, the propensity to drink frequently, and the propensity to be drunk frequently were lower than in states with lower beer taxes. Overall, it is estimated that about two-thirds of the ''economic costs'' of alcohol use and misuse are due to reductions in productivity, notes Mullahy, who has written many papers himself on the impact of alcohol on the economy. Very rough estimates of the total cost of abuse of the drug on the economy run around $100 billion a year, Mullahy says.