The canonical difference-in-differences (DD) model contains two time periods, “pre” and “post”, and two groups … effects change over time. I propose a new balance test derived from a unified definition of common trends. I show how to … time fixed effects, control for unit-specific time trends, or exploit a third difference …

induce delayed claiming was about $60,400, while when part-time work was required, the average was $66,700. This implies a …

Participation (SIPP). We then exploit variation in laws governing divorce across states and over time to quasi … divorce significantly increases the probability of full-time employment later in life, and significantly decreases retirement … does not impact full-time employment after age 50 but is positively associated with investment in education post marriage …

of 52 countries during the globalization period 1988-2006 strongly supports the model. Results solve several time …

winners from the first study cohort were slightly less likely to graduate on time than control applicants, suggesting that …

dynamic trading model, in which traders receive private information of asset value over time and trade strategically with … characterized explicitly in closed form. Infrequent trading (few double auctions per unit of time) leads to a larger market depth in …

average returns. This rules out typical risk-based explanations and is a challenge to structural models of time …

balance observables within firm, over time by developing weights through a machine learning algorithm. We find that spending …