The Heterogeneous Effects of P2P Ride-Hailing on Traffic: Evidence from Uber’s Entry in California

Despite their promise, popularity, and rapid growth, the transit implications of ride-hailing platforms (e.g., Uber, Lyft) are not altogether clear. On the one hand, ride-hailing services can provide pooling (i.e., traffic reductions) advantages by efficiently matching customer demand (i.e., trips) with resources (i.e., cars) or by facilitating car-sharing. On the other hand, ride-hailing may also induce extra travel because of increased convenience and travel mode substitution, which may create crowding (i.e., traffic increases). We seek to reconcile these divergent perspectives here, exploring the heterogeneous determinants of ride-hailing’s effects. Taking advantage of Uber’s staggered entry into various geographic markets in California, we execute a regression-based difference-in-differences analysis to estimate the impact of ride-hailing services on traffic volumes. Using monthly micro data from more than 9,000 vehicle detector station units deployed across California, we show that Uber’s effect (either pooling or crowding) on traffic depends on various contextual factors. We find some evidence of pooling effects on weekdays; however, Uber’s entry leads to significant crowding effects on weekends. Furthermore, the crowding effect is amplified on interior roads and in areas characterized by high population density. Although ride-hailing seems to have a substitution effect on public transportation, we find ride-hailing services may have a complementary effect for carpooling users. Finally, we show that premium ride-hailing services (e.g., Uber Black) almost exclusively lead to a crowding effect. We conduct a battery of robustness tests (e.g., propensity score matching, alternative treatment approaches, placebo tests) to ensure the consistency of our findings.

Confidence Interval for Change Point in Hazard Rate With Staggered Entry

We consider the construction of a con?dence region (interval) for a change point in hazard rate of the patients survival distribution when the patients enter the trial at random times. We show that the local- likelihood ratio process converges weakly to a certain process and obtain the maximum distribution of the process which does not depend on the change point, and thus can be used to construct the confidence region for the change point. We also compare the limiting density function to the empirical density and discuss the empirical coverage probability of the confidence interval by simulation. Stanford Heart Transplant data are used for illustration.

Learning about Competitors: Evidence from SME Lending

We study how small and medium enterprise (SME) lenders react to information about their competitors’ contracting decisions. To isolate this learning from lenders’ common reactions to unobserved shocks to fundamentals, we exploit the staggered entry of lenders into an information-sharing platform. Upon entering, lenders adjust their contract terms toward what others offer. This reaction is mediated by the distribution of market shares: lenders with higher shares or that operate in concentrated markets react less. Thus, contract terms are shaped not only by borrower or lender fundamentals but also by the interaction between information availability and competition.

Index Fund Entry and Financial Product Market Competition

The active money management industry is characterized by both strong competitive pressure from passive investment vehicles and high fees. This paper investigates how the introduction of low-cost index funds affects fund company strategies. The retail mutual fund market is segmented, where unsophisticated investors rely on financial advisers and sophisticated ones invest directly. Exploiting the staggered entry of low-cost Vanguard index funds as competitive shocks, I show that, in response to competition, incumbents sold to self-directed investors reduce their fees by 5% of the mean; however, funds sold with broker recommendations increase their fees by 6% of the mean. Index fund entry also slows the growth of actively managed funds. The responsiveness of broker-sold fund flows to distribution fees increases, suggesting a shift in composition toward less elastic consumers. Further, incumbents increase the degree of active management. The results illustrate why mutual fund fees slowly decline in the aggregate despite competition from lower-cost alternatives. This paper was accepted by Gustavo Manso, finance.

Do Managers Matter? A Natural Experiment from 42 R&D Labs in India

We exploit plausibly exogenous variation in the staggered entry of new managers into India’s 42 public R&D labs between 1994 and 2006 to study how alignment between the CEO and middle-level managers affects research productivity. We show that the introduction of new lab managers aligned with the national R&D reforms raised patenting and multinational licensing revenues by 58% and 75%, respectively, and scientist research productivity, including: a 16%, 10%, 11%, and 22% increase in h-indices, number of coauthors, publications, and citations per scientist, respectively. Using natural language processing techniques on the set of research abstracts produced among these scientists, we also find that overall mood and sentiment increased by 8.5% following the first managerial change. (JEL L22, L23, O32, O33)