Working papers results
We evaluate linear stochastic discount factor models using an ex-post portfolio metric: the realized out-of-sample Sharpe ratio of mean-variance portfolios backed by alternative linear factor models. Using a sample of monthly US portfolio returns spanning the period 1968-2016, we find evidence that multifactor linear models have better empirical properties than the CAPM, not only when the cross-section of expected returns is evaluated in-sample, but also when they are used to inform one-month ahead portfolio selection. When we compare portfolios associated to multifactor models with mean-variance decisions implied by the single-factor CAPM, we document statistically significant differences in Sharpe ratios of up to 10 percent. Linear multifactor models that provide the best in-sample fit also yield the highest realized Sharpe ratios.
The Italian civil war and the Nazi occupation of Italy occurred at a critical juncture, just before the birth of a new democracy. We study the impact of these traumatic events by exploiting geographic heterogeneity in the duration and intensity of civil war, and the persistence of the battlefront along the "Gothic line" cutting through Northern-Central Italy. We find that the Communist Party gained votes in postwar elections where the Nazi occupation lasted longer, mainly at the expense of centrist parties. This effect persists until the late 1980s and appears to be driven by equally persistent changes in political attitudes.