Sokbae Lee is a Professor at Columbia University and a Research Fellow at the IFS. He also works with the the Centre of Microdata Methods and Practice (cemmap) and is a Professor in the department of economics at Columbia University. His research focuses on theoretical and applied econometrics.
In parametric models a sufficient condition for local idenfication is that the vector of moment is differentiable at the true parameter with full rank derivative matrix. This paper shows that additional conditions are often needed in nonlinear, nonparametric models to avoid nonlinearities overwhelming linear effects.
This paper provides a practical and novel method for inference on intersection bounds, namely bounds defined by either the infimum or supremum of a parametric or nonparametric function, or equivalently, the value of a linear programming problem with a potentially infinite constraint set.
The authors work with a framework established by Blau and Kahn (1997 JOLE; 2006 ILRR), who used the Michigan Panel of Income Dynamics (PSID) to decompose that gap into observable and unobservable components in order to determine which contributing factors are gender-specific and which can be attributed to the wage structure.
This paper presents new evidence that increases in college enrollment lead to a decline in the average quality of college graduates between 1960 and 2000, resulting in a decrease of 6 percentage points in the college premium.
We examine the "home bias" of knowledge spillovers (the idea that knowledge spreads more slowly over international boundaries than within them) as measured by the speed of patent citations.
This paper develops a concrete formula for the asymptotic distribution of two-step, possibly non-smooth semiparametric M-estimators under general misspecification.
Lord Browne's recommendations for higher education funding have provoked controversy. The potential sharp increase in tuition fees has grabbed the headlines, but another proposed measure has also received considerable attention: increasing the interest rate on student loans to 2.2% above RPI inflation. There have also been criticisms of the review's alleged lack of focus on the potential for a graduate tax. In this Observation, we explore both issues in some detail.
This paper develops a concrete formula for the asymptotic distribution of two-step, possibly non-smooth semiparametric M-estimators under general misspecification.
This paper is concerned with inference about a function <i>g</i> that is identified by a conditional quantile restriction involving instrumental variables.
