Columbia Business School Research

Companies in a variety of industries (e.g., airlines, hotels, theaters) often use last-minute sales to dispose of unsold capacity. Although this may generate incremental revenues in the short term, the long-term consequences of such a strategy are not immediately obvious: More discounted last-minute tickets may lead to more consumers anticipating the discount and delaying the purchase rather than buying at the regular (higher) prices, hence potentially reducing revenues for the company.

Valuations of entrepreneurial companies are only observed occasionally, albeit more frequently for well-performing companies. Consequently, estimators of risk and return must correct for sample selection to obtain consistent estimates. We develop a general model of dynamic sample selection and estimate it using data from venture capital investments in entrepreneurial companies. Our selection correction leads to markedly lower intercepts and higher estimates of risks compared to previous studies.

Teaching may be the most-scrutinized occupation in the economy. Over the past four decades, empirical researchers—many of them economists—have accumulated an impressive amount of evidence on teachers: the heterogeneity in teacher productivity, the rise in productivity associated with teaching credentials and on-the-job experience, rates of turnover, the costs of recruitment, the relationship between supply and quality, the effect of class size and the monetary value of academic achievement gains over a student's lifetime.

In November of 2007, the New York City Department of Education assigned each elementary and middle school a letter grade (A to F) as part of a new accountability system. Grades were based on continuous numeric scores derived from levels and changes in student achievement and other school environmental factors such as attendance, and were linked to a system of rewards and consequences for schools and principals. We use the discontinuities in the assignment of grades to estimate the impact of accountability in the short run.

Active investors provide entrepreneurs with risk-sharing and value-adding effort, e.g., in form of advising, networking and monitoring. However, holdup problems may create a conflict between two key objectives for high-quality entrepreneurs: to elicit investor effort and to credibly signal their firm type by retaining shares. As a result, pooling of startup firms of different types may arise, in particular when investor effort is essential. More established firms, with access to multiple signals, can always realize both of these objectives.

In this paper, we measure the extent to which subjective and objective evaluations of new teachers in New York City can predict their future impacts on student achievement. Specifically, we examine evaluations of applicants to an alternative certification program, evaluations of new teachers by mentors that work with them during their first year, and evaluations based on student achievement data from their first year of teaching. We use a large sample, relative to prior work, and, unlike other studies (with the exception of John H. Tyler et al.

The fields of statistics and econometrics have developed powerful methods for testing the validity (specification) of a model based on its fit to underlying data. Unlike statisticians, managers are typically more interested in the performance of a decision rather than the statistical validity of the underlying model. We propose a framework and a statistical test that incorporates decision performance into a measure of statistical validity. Under general conditions on the objective function, asymptotic behavior of our test admits a sharp and simple characterization.

The present research explores how people's place in a power hierarchy alters their representations of valued objects. The authors hypothesized that powerlessness produces an accentuation bias by altering the physical representation of monetary objects in a manner consistent with the size-to-value relationship. In the first three experiments, powerless participants, induced through episodic priming or role manipulations, systematically overestimated the size of objects associated with monetary value (i.e., quarters, poker chips) compared to powerful and baseline participants.

We study the economic sources of stock-bond return comovements and their time variation using a dynamic factor model. We identify the economic factors employing a semistructural regime-switching model for state variables such as interest rates, inflation, the output gap, and cash flow growth. We also view risk aversion, uncertainty about inflation and output, and liquidity proxies as additional potential factors.

Using micro data on virtually all of the drugs and diseases of over 500,000 people enrolled in Puerto Rico's Medicaid program, the impact of the vintage (original FDA approval year) of drugs used to treat a patient on the patient's three-year probability of survival, controlling for demographic characteristics (age, sex, and region), utilization of medical services, and the nature and complexity of illness are examined. It is found that people using newer drugs during January-June, 2000, were less likely to die by the end of 2002, conditional on the covariates.

We examine the influence of an interstate network created by intergovernmental organizations (IGOs) on the global diffusion of democracy. We propose that IGOs facilitate democracy's diffusion by transmitting information between member states and by interpreting that information according to prevailing norms in the world society, where democracy is viewed as the legitimate form of government. We employ a network autocorrelation model to track changes in democracy among all of the world's countries from 1815 to 2000.

Hospital ambulance diversions are prevalent and increasing nationwide as emergency departments experience growing congestion. Using negative binomial regressions, this paper links the number of acute myocardial infarction (AMI) deaths to the level and extent of diversion in the five boroughs of New York City. The results indicate that both high levels of ambulance diversion and simultaneous diversion across hospitals are associated with increasing numbers of deaths from AMI.

Prices are typically used as proxies for countries' export quality. I relax this strong assumption by exploiting both price and quantity information to estimate the quality of products exported to the U.S. Higher quality is assigned to products with higher market shares conditional on price. The estimated qualities reveal substantial heterogeneity in product markets' scope for quality differentiation, or their "quality ladders." I use this variation to explain the heterogeneous impact of low-wage competition on U.S. manufacturing employment and output.

Power — asymmetric control over valued resources — is a fundamental dimension of social relations. Classical conceptualizations of power emphasize its conscious nature. In this review, we reveal how power often operates nonconsciously and identify the different methods and paradigms used to activate or create a psychological sense of power outside of conscious awareness.

The banking legislation of the 1930s took very little time to pass, was unusually comprehensive, and unusually responsive to public opinion. Ironically, the primary motivations for the main bank regulatory reforms in the 1930s (Regulation Q, the separation of investment banking from commercial banking, and the creation of federal deposit insurance) were to preserve and enhance two of the most disastrous policies that contributed to the severity and depth of the Great Depression — unit banking and the real bills doctrine.

Paid placements on search engines reached sales of nearly $11 billion in the United States last year and represent the most rapidly growing form of online advertising today. In its classic form, a search engine sets up an auction for each search word in which competing websites bid for their sponsored links to be displayed next to the search results.

This paper explores the aggregate consequences of Foreign Direct Investment (FDI) on the opportunities for risk diversification available to consumers. The crucial difference between FDI and other international financial flows is that the former involves technology flows across countries. We present a model where firm-embedded productivity can be transferred costly across countries through the activity of multinational firms.

Based on the symbolic association between physical and moral purity, we introduce a provocative possibility: clean smells might not only regulate physical cleanliness, but may also motivate virtuous behavior. Indeed, moral transgressions can engender literal feelings of dirtiness (Zhong & Liljenquist, 2006). Just as many symbolic associations are reciprocally related (Lakoff, 1987), such as coldness and loneliness (Zhong & Leonardelli, 2008) or darkness and depravity (Frank & Gilovich, 1988), morality and cleanliness may also be reciprocally linked.

Wal-Mart has increasingly become the target of protests over its scale, manifested as contention over specific expansions. Often, the protests are local and led by local organizations, and as a result, chains face uncertainty whether local activists will organize a protest. We suggest that chain stores respond to this uncertainty through a "test for protest" approach. They use low-cost probes that take the form of proposals to open a store.

Although established money managers operate in an environment which seems com- petitive, they also seem to be very profitable. The present value of the expected future profits from managing a collection of funds is equal to the value of the assets under management times the profit margin, assuming that the managed funds will remain in business forever, zero asset flow into and out of the funds, zero excess returns net of trading costs, fixed management fee proportional to the assets under management and a fixed profit margin for the management company.

Climate change, as a slow and gradual modification of average climate conditions, is a difficult phenomenon to detect and track accurately based on personal experience. Insufficient concern and trust also complicate the transfer of scientific descriptions of climate change and climate variability from scientists to the public, politicians, and policy makers, which is not a simple transmission of facts.

The current research examined the intersection of social categorization and identity recognition to investigate whether and when one form of construal would dominate people’s responses to social targets. Using an automatic priming paradigm and manipulating prime duration to examine how familiarity with social targets and the time course of processing moderate construal, we asked participants to judge the familiarity and sex of faces (Experiments 1 and 2, respectively).

Research suggests that living in and adapting to foreign cultures facilitates creativity. The current research investigated whether one aspect of the adaptation process — multicultural learning — is a critical component of increased creativity. Experiments 1-3 found that recalling a multicultural learning experience: (a) facilitates idea flexibility (e.g., the ability to solve problems in multiple ways), (b) increases awareness of underlying connections and associations, and (c) helps overcome functional fixedness.

This article provides a comprehensive analysis of a new and increasingly important phenomenon: the simultaneous holding of both equity and debt claims of the same company by non-commercial banking institutions ("dual holders"). The presence of dual holders offers a unique opportunity to assess the existence and magnitude of shareholder-creditor conflicts. We find that syndicated loans with dual holder participation have loan yield spreads that are 18–32 bps lower than those without. The difference remains economically significant after controlling for the selection effect.

We document the first systematic evidence on the characteristics and economic consequences of firms subject to employee allegations of corporate financial misdeeds. First, compared to a control group that avoided public whistle-blowing allegations, firms subject to whistle-blowing allegations were characterized by unique firm-specific factors that led employees to expose alleged financial misdeeds.

Why do affective forecasting errors persist in the face of repeated disconfirming evidence? Six studies indicate that people fail to perceive the extent of their forecasting error because they do not accurately remember their forecast. In the context of a Super Bowl loss (Study 1), a presidential election (Studies 2A, 2B, and 3), an important purchase (Study 4), and the consumption of a sequence of candies (Study 5), individuals mispredicted their affective reactions to these experiences, but subsequently misremembered their predictions as more accurate than they had actually been.

Previous research has identified four sources of brand equity: (1) biased perceptions; (2) image associations; (3) incremental value, a component that that is not related to product attributes or benefits; and (4) inertia value. This article develops a utility model that captures all these sources of brand equity; in particular, the model provides estimates of consumer-level brand equity at different levels of aggregation and also estimates firm-level brand equity.

We characterize the equilibrium behavior in a broad class of competition models in which the competing firms' market shares are given by an attraction model, and the aggregate sales in the industry depend on the aggregate attraction value according to a general function. Each firm's revenues and costs are proportional with its expected sales volume, with a cost rate that depends on the firm's chosen attraction value according to an arbitrary increasing function.

Consumers learn quality of many durable products through word-of-mouth information while firms launch new and improved products frequently in these markets. This paper examines firm incentives to invest in R&D to compete for patents in markets where consumers rely on word-of-mouth information and have expectations about the new products before launch. When its loss due to a possible entry is above a threshold, an incumbent has more incentives than a potential entrant to invest in R&D for patents.

We examine international stock return comovements using country-industry and country-style portfolios as the base portfolios. We first establish that parsimonious risk-based factor models capture the data covariance structure better than the popular Heston-Rouwenhorst (1994) model. We then establish the following stylized facts regarding stock return comovements. First, there is no evidence for an upward trend in return correlations, except for the European stock markets. Second, the increasing importance of industry factors relative to country factors was a short-lived phenomenon.

Under accrual accounting, earnings add to shareholders' equity. Cash flow generated by a business has no effect on the book value of shareholders' equity but reduces the book value of net assets employed in business operations. In short, accrual accounting rules prescribe that earnings add to shareholder value, but cash flow is irrelevant to the valuation of equity. This paper documents that the stock market prices equity shares according to this prescription.

We consider a single product revenue management problem where, given an initial inventory, the objective is to dynamically adjust prices over a finite sales horizon to maximize expected revenues. Realized demand is observed over time, but the underlying functional relationship between price and mean demand rate that governs these observations (otherwise known as the demand function or demand curve), is not known.

We analyze a planning model for a firm or public organization that needs to cover uncertain demand for a given item by procuring supplies from multiple sources. The necessity to employ multiple suppliers arises from the fact that when an order is placed with any of the suppliers, only a random fraction of the order size is usable. The model considers a single demand season with a given demand distribution, where all supplies need to be ordered simultaneously before the start of the season.

We consider a revenue maximizing make-to-order manufacturer that serves a market of price and delay sensitive customers and operates in an environment in which the market size varies stochastically over time. A key feature of our analysis is that no model is assumed for the evolution of the market size. We analyze two main settings: i) the size of the market is observable at any point in time; and ii) the size of the market is not observable and hence cannot be used for decision-making.