The study produced six significant findings. One finding was that historical data on local policy change regarding underage drinking was difficult to obtain. A second finding related to methodology was the successful development of an index of alcohol policy that seems to have some predictive validity (the Policy Score). It would be useful to replicate and test this index in future research. A third finding relates to the scope of the policies identified. Some policy domains with the potential to contribute to countering underage drinking were not used. These policies should be implemented and tested at both the State and local levels. A fourth finding was that the policy index was related to the lower prevalence of attendance at underage drinking parties among underage youth. A fifth finding was a positive link between the tax score and party-going; this suggests that communities that enact local tax authority may want to address underage drinking parties through both enforcement efforts and policies to discourage the hosting of such parties. The sixth finding was the lack of a consistent relationship between enforcement efforts and the prevalence of underage drinking. This should be a key area for future research. 7 tables, 55 references, and appended policy-tracking codebook