Long days have become a status symbol. This is bad for both genders.

Research shows that men prefer female partners who are less professionally ambitious than they are. Because of this, many single women face a trade-off: actions that lead to professional success might be viewed less favorably in the heterosexual marriage market. A new study involving more than 300 MBA students shows how this trade-off plays out. When filling out questionnaires or surveys about ideal jobs, single women who thought their answers would be available to male classmates lowered their desired yearly compensation from $131,000 to $113,000 on average and their willingness to travel from 14 days to 7 days per month. They also reported wanting to work four fewer hours per week. Women who were married or in a relationship did not show this pattern, and neither did men (regardless of their relationship status). The results suggest that marriage considerations may be an additional explanation for gender differences in the labor market.

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A look through HBR’s archives shows that business thinkers use the concept of a “business model” in many different ways, potentially skewing the definition. Many people believe Peter Drucker defined the term in a 1994 article as “assumptions about what a company gets paid for,” but that article never mentions the term business model. Instead, Drucker’s theory of the business was a set of assumptions about what a business will and won’t do, closer to Michael Porter’s definition of strategy. Businesses make assumptions about who their customers and competitors are, as well as about technology and their own strengths and weaknesses. Joan Magretta carries the idea of assumptions into her focus on business modeling, which encompasses the activities associated with both making and selling something. Alex Osterwalder also builds on Drucker’s concept of assumptions in his “business model canvas,” a way of organizing assumptions so you can compare business models. Introducing a better business model into an existing market is the definition of a disruptive innovation, as written about by Clay Christensen. Rita McGrath offers that your business model is failing when innovations yield smaller and smaller improvements. You can innovate a new model by altering the mix of products and services, postponing decisions, changing the people who make the decisions, or changing incentives in the value chain. Finally, Mark Johnson provides a list of nineteen types of business models and the organizations that use them.