In specifications of tastes and technology, econometricians often impose curvature globally, but monotonicity only locally or not at all. In fact monotonicity rarely is even mentioned in that literature. But without satisfaction of both curvature and monotonicity, the second order conditions for...

It has long been rumored among European economists that Theil had a difficult time in The Netherlands during the Second World War, but few, if any, economists knew what actually happened to him. Following Theil's retirement from the U. of Florida, I visited with him in St. Augustine, where Hans...

Although nonlinearity is the rule in economic theory, nonlinearity tends to make life difficult for econometricians. While there have been many advances in nonlinear econometrics in recent years, some problems produced by nonlinearity remain 'skeletons in the closet' in empirical economic...

This paper consists of the page proofs of W. A. Barnett's interview of Paul A. Samuelson, to appear in print in the journal, Macroeconomic Dynamics, in September 2004. To our knowledge, this is the first and only interview of Paul A. Samuelson published in a professional economics journal. In...

In aggregation theory, index numbers are judged relative to their ability to track the exact aggregator functions nested within the economy's structure. Within the monetary sector, Barnett, Liu, and Jensen (1997) compared two statistical index numbers: the Divisia monetary aggregate and the...

Euler equation models represent an important class of macroeconomic systems. Our ongoing research (He and Barnett (2003)) on the Leeper and Sims (1994) Euler equations macroeconometric model is revealing the existence of singularity-induced bifurcations, when the model’s parameters are within...

In aggregation theory, the admissibility condition for clustering together components to be aggregated is blockwise weak separability, which also is the condition needed to separate out sectors of the economy. Although weak separability is thereby of central importance in aggregation and index...