Surveys are an important tool in economics and in the social sciences more broadly. However, methods used to analyse ordinal survey data (e.g., ordered probit) rely on strong and often unjustified distributional assumptions. In this paper, we propose using survey response times to solve that...

Surveys that measure subjective states like happiness or preferences often generate discrete ordinal data. Ordered response models, which are commonly used to analyze such data, suffer from a fundamental identification problem. Their conclusions depend on unjustified assumptions about the...

Surveys that measure subjective states like happiness or preferences often generate discrete ordinal data. Ordered response models, which are commonly used to analyze such data, suffer from a fundamental identification problem. Their conclusions depend on unjustified assumptions about the...

Surveys that are designed to measure subjective states (e.g., happiness) typically generate ordinal data. A fundamental problem is that methods used to analyse ordinal data (e.g., ordered probit) rely on strong and often unjustified distributional assumptions. In this paper, we propose using...

This article examines the effects of market structure on the variety of research projects undertaken and the amount of duplication of research. A characterization of the equilibrium market portfolio of R&D projects and the socially optimal portfolio is provided. It is shown that a merger...

This paper develops an innovation model where firms choose which research paths to follow. Contrary to most of the literature which focuses only on the level of investment in innovation, this model captures both the variety of research paths undertaken and the amount of duplication of research....

When firms decide to invest in R&D, they have to choose not only the amount of resources to invest, but also which research projects to develop. This paper investigates the market portfolio of research projects. Contrary to most of the literature, which focuses only on the level of investment in...