Product Differentiation, Search Costs, and Competition in the Mutual Fund Industry: A Case Study of the S&P 500 Index Funds

Two salient features of the competitive structure of the U.S. mutual fund industry are the large number of funds and the sizeable dispersion in the fees funds charge investors, even within narrow asset classes. Portfolio financial performance differences alone do not seem able to fully explain these features. We investigate whether non-portfolio fund differentiation and information/search frictions also play a role in creating these observed industry characteristics. We focus on their impact in a case study of the retail S&P 500 index funds sector. We find that fund proliferation and price dispersion also exist in this sector, despite the funds' financial homogeneity. Furthermore, there was a marked shift in sector assets to more expensive (often newly entered) funds throughout our sample period. Our analysis indicates that these observations are consistent with the presence of both non-portfolio differentiation and information/search frictions. Structural estimation of a novel search-over-differentiated-products model reveals that reasonable magnitudes of investor search costs can explain the considerable price dispersion in the sector, and consumers seem to value funds'' observable attributes such as fund age and the number of other funds in the same fund family in largely plausible ways. The results also suggest that the substantial increase in mutual fund market participation observed during our sample, and the corresponding purchase decisions of novice investors, drove the shift in assets toward more expensive funds. We also find evidence consistent with the presence of switching costs, as distinct from search costs. Using structural estimates of demand parameters and search costs, we investigate the possibility that there are too many sector funds from a social welfare standpoint. The results of this exercise indicate that restricting entry would yield nontrivial gains from reduced search costs and productivity gains from scale economies, but these may be counterbalanced by losses from increased market power and reduced product variety.

How do Incumbents Respond to the Threat of Entry? Evidence from the Major Airlines

We examine how incumbents respond to the threat of entry by competitors (as distinct from how they respond to actual entry). We look specifically at passenger airlines, using the evolution of Southwest Airlines’ route network to identify particular routes where the probability of future entry rises abruptly. We find incumbents cut fares significantly when threatened by Southwest’s entry. Over half of Southwest’s total impact on incumbent fares occurs before Southwest starts flying. These cuts are only on threatened routes, not those out of non-Southwest competing airports. The evidence on whether incumbents are seeking to deter or accommodate entry is mixed.

Product Substitutability and Productivity Dispersion

There are tremendous across-plant differences in measured productivity levels, even within narrowly defined industries. Most of the literature attempting to explain this heterogeneity has focused on technological (supply-side) factors. However, an industry's demand structure may also influence the shape of its plant-level productivity distribution. This paper explores the role of one important element of demand, product substitutability. The connection between substitutability and the productivity distribution is intuitively straightforward. When industry consumers can easily switch between suppliers, it is more difficult for relatively inefficient (high-cost) producers to profitably operate. Increases in product substitutability truncate the productivity distribution from below, implying less productivity dispersion and higher average productivity levels in high-substitutability industries. I demonstrate this mechanism in a simple industry equilibrium model, and then test it empirically using plant-level data from U.S. manufacturing industries. I find that as predicted, product substitutability measured in several ways is negatively related to within-industry productivity dispersion and positively related to industries' median productivity levels.

The importance of measuring dispersion in firm-level outcomes

Recent research has revealed enormous variation in performance and growth among firms, which both drives and is driven by large reallocations of inputs and outputs across firms (churning) within industries and markets. These differences in firm-level outcomes and the associated turnover of firms affect many economic policies (both labor- and non-labor-oriented), on both a microeconomic and a macroeconomic scale, and are affected by them. Properly evaluating these policies requires familiarity with the sources and consequences of firm-level variation and within-industry reallocation

Cementing Relationships: Vertical Integration, Foreclosure, Productivity, and Prices

This paper empirically investigates the possible market power effects of vertical integration proposed in the theoretical literature on vertical foreclosure. It uses a rich data set of cement and ready-mixed concrete plants that spans several decades to perform a detailed case study. There is little evidence that foreclosure is quantitatively important in these industries. Instead, prices fall, quantities rise, and entry rates remain unchanged when markets become more integrated. These patterns are consistent, however, with an alternative efficiency-based mechanism. Namely, higher productivity producers are more likely to vertically integrate and are also larger, more likely to survive, and charge lower prices. We find evidence that integrated producers' productivity advantage is tied to improved logistics coordination afforded by large local concrete operations. Interestingly, this benefit is not due to firms' vertical structures per se: non-vertical firms with large local concrete operations have similarly high productivity levels.

The Slow Growth of New Plants: Learning about Demand?

It is well known that new businesses are typically much smaller than their established industry competitors, and that this size gap closes slowly. We show that even in commodity-like product markets, these patterns do not reflect productivity gaps, but rather differences in demand-side fundamentals. We document and explore patterns in plants’ idiosyncratic demand levels by estimating a dynamic model of plant expansion in the presence of a demand accumulation process (e.g., building a customer base). We find active accumulation driven by plants’ past production decisions quantitatively dominates passive demand accumulation, and that within-firm spillovers affect demand levels but not growth.