This paper proposes a representative agent habit-formation model where preferences are defined for both luxury goods and basic goods. The model matches the equity risk premium, risk-free rate, and volatilities. From the intratemporal first-order condition, one can substitute out basic good consumption and the habit level, yielding a stochastic discount factor driven by two observable risk factors: luxury good consumption and the relative price of the two goods. I estimate these processes and find them to be heteroskedastic, implying time variation in the conditional volatility of the stochastic discount factor. These dynamics occur both at the business cycle frequency and at a lower, “generational” frequency. The findings reveal that the time variation in aggregate stock market and Treasury bond risk premiums are consistent with the predictions of the model.