An important contention of Proposition 13's proponents was that a tax reduction would boost economic activity. It is too early to ascertain whether or not this has happened in California. This study addresses the issue in a more general context by attempting to answer the question: Do state and local taxes affect economic growth? Economic theory tells us that a change in the level of state and local taxes might affect economic growth in a number of ways, but the direction of the net result is not obvious. The methodology used here is multiple regression analysis across states. The major contribution of this study is the use of other variables besides taxes to explain growth in personal income, reducing possible biases in the results of previous work in this area. The results of this study indicate that state and local taxes may be a significant deterrent to growth in personal income.