We use the exchange between Kearney/Levine and Jaeger/Joyce/Kaestner on “16 and Pregnant” to reexamine the use of DiD as a response to the failure of nature to properly design an experiment for us. We argue that 1) any DiD paper should address why the original levels of the experimental and...

Ultra-high frequency data are complete transactions data which inherently arrive at random times. Marked point processes provide a theoretical framework for analysis of such data sets. The ACD model developed by Engle and Russell (1995) is then applied to IBM transactions data to develop...

This paper studies the econometric problems associated with estimation of a stochastic process that is endogenously sampled. Our interest is to infer the law of motion of a discrete-time stochastic process {pt} that is observed only at a subset of times {t1,..., tn} that depend on the outcome of...

The financing of public employee pensions has become an issue of growing public concern. This paper examines the fundinq status of teacher pension plans for the fifty states and for selected localities for the decade, 1971-1980. A pension underfunding equation based upon actuarial principles is...

This essay sets out a framework for evaluating empirical work in terms of the ability of the data to provide adequate parameter estimates and hypothesis tests about the true underlying structure. Problems of aggregation, representativeness and structural change are discussed in detail. These...

The concept of Economic Reform is described as a planned shift from one, Pareto inefficient, but quasi-stable, equilibrium (or 'trap') to a new Pareto superior equilibrium which is, or is designed to become, stable too. The concept is applied to recent 'shock' stabilization programs, with...