This essay surveys the body of research that asks how the efficiency of corporate investment
is influenced by problems of asymmetric information and agency. I organize the material …

This paper argues that the documented discount on diversified firms is not per se evidence
that diversification destroys value. Firms choose to diversify. We use three alternative …

Potential diversification benefits are one reason why US financial holding companies are
offering a growing range of financial services. This paper examines whether the observed …

This paper investigates whether the diversity of activities conducted by financial institutions
influences their market valuations. We find that there is a diversification discount: The market …

We analyze several hundred firms that expand via acquisition and/or increase their number
of business segments. The combined market reaction to acquisition announcements is …

Using plant‐level observations from the Longitudinal Research Database I show that
conglomerates are more productive than stand‐alone firms at a given point in time …

Recent equity carve-outs in US technology stocks appear to violate a basic premise of
financial theory: identical assets have identical prices. In our 1998–2000 sample, holders of …

We exploit a novel setting in which the same piece of information affects two sets of firms:
one set of firms requires straightforward processing to update prices, while the other set …

We survey the recent developments in the literature on corporate diversification. This
literature is voluminous, diverse, and quite old. To make the task more manageable, we …

We decompose the cross‐sectional variance of firms' book‐to‐market ratios using both a
long US panel and a shorter international panel. In contrast to typical aggregate time‐series …