Accounts of economic change recognize that markets create selective pressures for the adaptation of technologies in the direction of customer needs and production efficiencies. However, non-adaptational bases for technological change are rarely highlighted, despite their pervasiveness in the history of technical and economic change. In this paper the concept of exaptation - a feature co-opted for its present role from some other origin - is proposed as a characteristic element of technological change, and an important mechanism by which new markets for products and services are created by entrepreneurs. Exaptation is shown to be a missing but central concept linking the evolution of technology with the entrepreneurial creation of new markets and the concept of Knightian uncertainty.

Component sharing - using the same version of a component across multiple products -is an approach adopted by many assembled product manufacturers to achieve high final product variety with lower component variety and cost. This paper presents a methodology for determining which versions of a set of related components should be offered to optimally support a defined finished product portfolio. We develop optimization models that determine which versions of each component should be introduced and which of these versions each product should use so as to minimize design and production costs. This approach is appropriate for components with a relatively low impact on consumers' perceptions about product differentiation, which can be shared across a set of products if they meet the most stringent performance requirements in the set. We illustrate our procedure on automotive braking systems, but also discuss it applicability to other components and industries. Finally, we consider organizational issues and identify three conceptually different approaches to component sharing: a coordinated projects approach that requires higher-level organizational echelons above the individual project, a project-by-project approach that does not, and a hybrid partially coordinated approach. We use our model to show that the gain from the coordinated projects approach relative to the project-by-project approach is increasing in the number of component versions in consideration and warrantee and complexity costs, but does not vary systematically with product demand variability. Further, we use our model to highlight the risk of using simplistic heuristics to determine design sequence within a component system in a partially coordinated approach. We find that this approach is not always superior to the project-by-project approach, despite requiring greater coordination.

Variety management has emerged as a crucial dimension of successful business practice. In this paper, I first provide a framework for managerial decisions about variety. Variety-creation decisions determine the amount, type, and timing of end-product variety, while variety-implementation decisions focus on the design and operation of internal processes and a supply chain to support a firm's variety-creation strategy. I organize variety-related decisions into four key decision themes in variety creation: 1) dimensions of variety, 2) product architecture, 3) degree of customization, and 4) timing; and three key decision themes in variety implementation: 1) process capabilities, 2) points of variegation, and 3) day-to-day decisions. I describe each theme and review the relevant literature on each theme, with a focus on research that provides insight to problems faced in practice. Finally, I identify untapped avenues for future research that would be of value to the practicing manager, paying special attention to interdependencies among decision themes.

Product variety in many industries has increased steadily throughout this century. Component sharing-using the same version of a component across multiple products-is increasingly viewed by companies as a way to offer high variety in the marketplace while retaining low variety in their operations. Yet, despite the popularity of component sharing in industry, little is known about how to design an effective component-sharing strategy or about the factors that influence the success of such a strategy. In this paper we critically examine component sharing using automotive front brakes as an example. We consider three basic questions: (1) What are the key drivers and trade-offs of component-sharing decisions? (2) How much variation exists in actual component-sharing practice? and (3) How can this variation be explained? To answer these questions, we develop an analytic model of component sharing and show through empirical testing that this model explains much of the variation in sharing practice for automotive braking systems. We find that the optimal number of brake rotors is a function of the range of vehicle weights, sales volume, fixed component design and tooling costs, variable costs, and the variation in production volume across the models of the product line. We conclude with a discussion of the general managerial implications of our findings.

This essay connects four key ideas from Herbert Simon's "Sciences of the Artificial" to recent research on entrepreneurial expertise: (1) natural laws constrain but do not dictate our designs; (2) we should seize every opportunity to avoid the use of prediction in design; (3) locality and contingency govern the sciences of the artificial; and, (4) near-decomposability is an essential feature of enduring designs. The essay is based on a series of conversations and emails with Simon about the empirical findings of my doctoral dissertation that involved a protocol analysis study of expert founder-entrepreneurs.

Current perceptions and practices in doctoral education in the field of entrepreneurship are explored. The paper developed from efforts of a Task Force formed by the Entrepreneurship Division of the Academy of Management in response to several important observations: growing demand for faculty in entrepreneurship, growing membership in the division, more participants in doctoral and junior faculty consortia, increasing attention to entrepreneurship education at all academic levels, and the implementation of more doctoral seminars and programs in the field. Using a process outlined in Summer et al. [J. Manage. 16 (1990) 361], the Task Force addressed the following questions: (1) What is the current state of doctoral education in entrepreneurship? (2) How should doctoral education in Entrepreneurship be designed? Recommendations are presented.

For almost fifty years now, following the trail of issues raised by economists such as Hayek, Schumpeter, Kirzner and Arrow, researchers have studied the economics of technological change and the problem of allocation of resources for invention (invention being the production of information). The bulk of this literature simply assumes that new technical information will either be traded as a commodity or become embodied in products and services (hereafter called 'economic goods'), without addressing any specific mechanisms or processes for the transformation of new information into new economic goods or new economic entities (such as new firms and new markets). It is inside this gap that we begin our quest for the concept of an "entrepreneurial opportunity."

In this lecture I wish to explore the possibility of a useful dialogue between the fields of entrepreneurship and business ethics for mutual benefit. Although these two fields have much to offer each other, they have developed largely independent of each other. I wish to argue that entrepreneurship has a role to play in stakeholder theory and, relatedly, that stakeholder theory enriches our understanding of the entrepreneurial process.

Variety management has emerged as a crucial dimension of successful business practice. In this paper, I first provide a framework for managerial decisions about variety. Variety-creation decisions determine the amount, type, and timing of end-product variety, while variety-implementation decisions focus on the design and operation of internal processes and a supply chain to support a firm's variety-creation strategy. I organize variety-related decisions into four key decision themes in variety creation: 1) dimensions of variety, 2) product architecture, 3) degree of customization, and 4) timing; and three key decision themes in variety implementation: 1) process capabilities, 2) points of variegation, and 3) day-to-day decisions. I describe each theme and review the relevant literature on each theme, with a focus on research that provides insight to problems faced in practice. Finally, I identify untapped avenues for future research that would be of value to the practicing manager, paying special attention to interdependencies among decision themes.

In economics and management theories, scholars have traditionally assumed the existence of artifacts such as firms/organizations and markets. I argue that an explanation for the creation of such artifacts requires the notion of effectuation. Causation rests on a logic of prediction, effectuation on the logic of control. I illustrate effectuation through business examples and realistic thought experiments, examine its connections with existing theories and empirical evidence, and offer a list of testable propositions for future empirical work.

In his book "Invention," Professor Norbert Wiener (1993), commenting on the relative importance accorded to individuals and institutions in historical narratives of science and inventions, asks us to imagine Shakespeare's "Romeo and Juliet" without either Romeo or the balcony. The story is just not the same. He likens much of the study of the economic history of science and accounts of inventions as "all balcony and no Romeo." The balcony for Norbert Wiener captures the context in which the story unfolds - the culture, the institutions, the constraints and the catalysts that move the plot forward and thicken it. Romeos, for Wiener, play the leading parts in the story, because there is a strong fortuitous element to inventions and there is no inevitability that a possible discovery will be made at a given time and space. Take away either one, Romeo or the balcony, and the whole story falls apart. In a similar vein, we would liken studies of strategic management to "all balcony and no Romeo." But if we accuse strategic management of being "all balcony and no Romeo," strategic management scholars could legitimately accuse entrepreneurship of being "all Romeo and no balcony."

November 14, 1997, Graduate School of Industrial Administration, Carnegie Mellon University, Pittsburgh, Pennsylvania Herbert Simon, the chairman of the panel, opened the proceedings by laying out the ground rules and objectives. He explained that the seminar was meant to be primarily a conversation among the participants with some inputs from the audience-a conversation, not to settle on a theory of entrepreneurship, but to determine some important research questions in trying to understand entrepreneurship, which he defined as the origins of new economic activity.

To date, the phenomenon of entrepreneurship has lacked a conceptual framework. In this note we draw upon previous research conducted in the different social science disciplines and applied fields of business to create a conceptual framework for the field. With this framework we explain a set of empirical phenomena and predict a set of outcomes not explained or predicted by conceptual frameworks already in existence in other fields.