Many firms like eBay do their business by acting as an intermediary, or platform, which enables interactions between two groups of users: sellers and buyers. Through this or other platforms, end-users on the two sides trade products or services and realize their cross-group benefits, and the platform operator profits by collecting usage fees from end-users onboard. In this economy, both end-users’ benefits and the platform’s profits depend heavily on how well the platform can help users to exploit their cross-group externality. This externality can involve end-users’ interdependence in two dimensions: quality and quantity. For instance, when a consumer visits an online trading platform, she cares not only about the number of sellers available to choose from but also about the quality of products these sellers provide.
Previous work on two-sided markets has mainly focused on the quantity externality; Little attention has been paid to the quality externality. Recent research by Jin Wang, Assistant Professor of Economics, proposes a model in which both quality and quantity play a role in the end-users’ interactions, and analyzes how platforms can use quality screening to alleviate the problem of asymmetric information of quality and motivate end-users’ participations. She addresses the question from theoretical and empirical perspectives. In the theory, she builds a model in which two platforms compete but only one of them screens sellers’ products. She shows that the quality screening influences consumers’ expectations of product quality and their choice of sellers and platforms. The resulting screening effect, together with the network and competition effects, further drives sellers to enter different platforms. Comparative static analysis indicates that sellers’ incentives to join the platform that screens products follow an inverted-U curve with respect to the observable quality of products. In the empirical study, she estimates the model with the data from Tmall and Taobao, two online trading platforms operated by Alibaba. The estimation results are consistent with the theory. The counterfactual analysis suggests that quality screening improves the consumers’ utility and helps to improve Alibaba’s market share.
Despite student debt exceeding credit card debt in magnitude, little is known about how people transition through the student loan repayment process and how student loans interact with other types of debt. Due to data availability, research on loan repayment tends to focus on whether individuals ever default or default rates at a certain point in time. Previous research has not examined how other debt an individual has impacts their student loan repayment decisions. It is important for researchers to have a better understanding on how people actually experience student loan repayment and learn what is associated with not paying student loans.
In a working paper with Dr. Chris Reynolds, a financial economist at the Office of the Comptroller of the Currency, Dr. Gaulke investigates who defaults on student loans over time, what is associated with default and regaining good standing on student loans (“curing”) and how people prioritize different types of debt. In the paper entitled "Student Loan Repayment", they find that the composition of student loan defaulters has changed greatly since 2005. Since then, student loan defaulters are more likely to default only on student loans and are less likely to default on student loans and other types of debt. For those who have multiple types of debt, but only default on student loans this indicates that student loans are less of a priority. For the group that defaults on multiple types of debt, they find that student loans to be more prioritized than many other types of debt (for example credit cards). They also find that, even controlling for credit score, balances of other types of debt and whether other debt is not being paid impacts the likelihood of default. Additionally, local labor markets matter as an increase in the county unemployment rate increases the likelihood of default and higher real wages in the county decreases the likelihood of default.
One of Philippe Belley's recent publication (coauthored with Guy Lacroix and Nathalie Havet) investigates the links between statistical discrimination, job changes, tenure and wage profiles in the early career of workers. Statistical discrimination arises in a labor market if employers have partial information about worker productivity, and if this information is somehow of poorer quality for a specific group of workers. In this recent publication, it is assumed that information about female workers' productivity is of poorer quality relative to male workers. Crucially it is also assumed that employers improve their knowledge of male workers productivity at a faster rate than female workers. These two assumptions yield numerous theoretical predictions pertaining to gender wage gaps and how it changes as young workers careers evolve. These predictions are tested using data from the 1979 cohort of the National Longitudinal Survey of Youth. As predicted, it is found that men and women have the same wage at the start of their career, but that female wages grow at a slower rate thus generating a gender wage gap.
In a recent unpublished paper (coauthored with Yang Jiao) empirical analysis shows that the returns of work experience to wage growth for women, i.e. the rate at which wages grow as workers accumulate experience, vary on the basis of whether they have children and the timing of their transition to motherhood, even after accounting for accumulated work experience, tenure, and time spent out of employment. This means that mothers may still have lower wages even if they work as much as women who have no children. Women who have their first child before the age of 25 (early mothers) experience weaker returns to work experience. Women who have their first child after the age of 25 (late mothers) experience stronger returns to work experience before becoming mothers, and see these returns decrease significantly after their first child is born. Philippe Belley's paper also considers the occupational tasks that women complete at work. It is found that both early and late mothers tend to climb the interpersonal tasks ladder at a faster rate than women who never transition to motherhood (non-mothers). Early mothers climb the cognitive tasks ladder at a slower rate than late mothers and non-mothers. Finally there is evidence that long birth related work interruptions that lead to wage losses are associated with mothers returning to jobs with lower (higher) cognitive (interpersonal) tasks requirement.
Measuring the effects of international trade on labor market outcomes has never been more important given the increasing interconnections among economies around the globe. However, using measures of exposure to trade flows based on gross exports may lead to a misleading picture given that production processes have essentially become globalized, allowing firms to have access to imported inputs as an example. Recent research by Leilei Shen, assistant professor of economics, in co-authorship with Peri da Silva, associate professor of economics, find that continuously rising exports from China to the U.S. do not have significant effects on employment and wages. They construct a measure of U.S. exposure to Chinese goods using value added trade to analyze its effects on U.S. local labor markets. They further decompose the measure of exposure into value added trade in intermediate and in final goods. In line with the theoretical framework, they find that an increase in value added exports from China in final goods leads to a decrease in employment across U.S. local labor markets, while the effects from a change in the exposure to trade in intermediate goods are not significant. Professor Shen and Professor Silva have been invited to present this research at numerous venues, including the Empirical Investigations in International Trade, hosted by the Forum for Research in Empirical International Trade in 2014, Midwest International Trade Meetings and ASSA Annual Meetings in Boston.
The area in economics in which I conduct research is known as Industrial Organization. Industrial organization is a sub-field of microeconomics that studies the functioning of imperfectly competitive markets. In particular, industrial organization is concerned with business behavior and strategy in imperfectly competitive markets, as well as the implications that such behavior and strategy have for economic welfare. A specific behavior of firms in imperfectly competitive markets that has received considerable attention from industrial organization economists is that of mergers between firms.
A merger is a transaction in which the assets of two or more firms are combined in a new firm. One of the central issues in industrial organization is how mergers affect firm conduct and market performance. Retrospective studies of mergers tend to focus on the price effects of the relevant merger. To wit, do we observe the merging firms increase or decrease the price of their products subsequent to merging? Assuming product quality is unchanged by the merger, consumer welfare is inversely related to the price change of the merged firm's products. However, due to reasons subsequently discussed below, a merged firm may produce products of different quality relative to pre-merger product quality, and changes in product quality directly affect consumer welfare.
Departing from the extant literature in industrial organization that largely focuses on the price effects of mergers, a recent research paper that I coauthored with Yongmin Chen (University of Colorado, Boulder), investigates how two recent airline mergers affect the quality of air travel products offered by the airlines that merged. The paper is entitled: “Mergers and Product Quality: Evidence from the Airline Industry.”
Why might mergers cause the quality of products offered by a merged firm to change relative to pre-merger product quality? The research paper posits two key effects through which a merger may influence product quality: (1) Coordination effect; and (2) Incentive effect.
The coordination effect is the situation in which a merger by two firms allows them to share technical information and coordinate production activities, which can positively affect the quality of their products. For example, an airline merger may allow the two airlines to coordinate their flight schedules to better serve consumer needs. On the other hand, the incentive effect occurs when a merger reduces the competitive pressure on the firms to improve product quality, which can negatively affect the quality of their products. For example, competing airlines in an origin-destination market may have each provided nonstop and intermediate stop(s) products prior to merging, but find it profitable to eliminate the more travel-convenient nonstop product post-merger. Therefore, using a simple theoretical model, we argue that whether a merger raises or lowers product quality depends crucially on the relative strengthens of the coordination and incentive effects.
The two airline mergers we study are: (1) Delta Airlines merger with Northwest Airlines, which occurred in 2008; and (2) United Airlines merger with Continental Airlines, which occurred in 2010.
The research focuses on a specific measure of air travel product quality, which we refer to as Routing Quality. Routing quality relates to the travel convenience of the product itinerary, and is measured by the percentage ratio of nonstop flight distance to the product's itinerary flight distance used to get passengers from the origin to destination. Therefore, the routing quality variable takes on only positive values, where the maximum value is 100 in the case that the product itinerary uses a single nonstop flight to get passengers from the origin to destination. The presumption is that, holding all other factors constant, passengers prefer an itinerary that uses the most direct routing to get to their destination, so a higher value of the routing quality measure is associated with a more passenger-desirable travel itinerary.
The empirical analysis focuses on a sample of US domestic air travel markets and yields two key findings.
First, we find that the mergers increased routing quality of the merging firms’ products in markets where the merging firms did not compete with each other prior to the merger. In these markets the negative incentive effect of the merger on product quality is absent since the merging firms did not compete with each other prior to their merger. Thus the positive effect of the mergers on product quality in these markets is driven by the coordination effect, i.e., the merging airlines coordinate their route networks to offer products with better routing quality for consumers in these markets.
Second, we find that the mergers decreased routing quality of the merging firms’ products in those markets in which the airlines directly competed prior to their merger. Since both the coordination and incentive effects of a merger on product quality are present in those markets, the evidence suggests that the negative incentive effect of the mergers is stronger than the positive coordination effect. In other words, in those markets the mergers serve to sufficiently reduce the competitive pressure on the airlines to maintain or improve product quality, thus resulting in products of lower quality post-merger.
Since changes in product quality directly affect consumer welfare, the evidence provided in this research suggests that the standard practice in merger reviews that consider mainly the price effects may lead to substantial under- or over-estimate of a merger’s consumer benefit or harm. It would thus be desirable to explicitly incorporate product quality considerations into merger reviews. The insights from this paper may stimulate further research on merger-specific quality considerations and thereby inform public policy on the merits of proposed mergers.
Philip Gayle presented this paper at The 12th Annual International Industrial Organization Conference, April 11-13, 2014, held at the Northwestern University Law Searle Center on Law, Regulation and Economic Growth. The paper is also currently under review at a peer-reviewed economics journal.
The formation of preferential trade agreements (PTAs) is among the most notorious features of the international trade system. These PTAs allow member countries to exchange preferential access to each other's markets while fulfilling their obligations to the World Trade organization (WTO). More than three hundred PTAs have been created since WWII and others are under negotiation among various countries. The North America Free Trade Area (NAFTA) and the European Union (EU) are some of the many examples of PTAs discussed in popular media channels. Most PTAs take the form of free trade areas (FTAs) and customs unions (CUs). The former allows member countries to set tariffs against non-members independently while the latter requires that member countries coordinate their external tariffs by imposing common external tariffs.
In a recent paper, assistant professor Peri da Silva, in co-authorship with Giovanni Facchini (Nottingham University) and Gerald Willmann (Bielefeld University), propose a political-economy of trade framework with which to understand the greater popularity of FTAs relative to CUs. In their paper, they consider the formation of preferential agreements between economies under the presence of geographic specialization, i.e., each prospective member produces a different set of final goods. Most of the literature finds that coordination of external tariffs leads to the conclusion that the average voter is better off under CUs than under FTAs. Prof. da Silva and co-authors show that this need not be the case. They show that tariff coordination leads voters to strategically delegate power to very protectionist representatives. This finding leads to the conclusion that the average voter may be better off under FTAs than under CUs. They also discuss the political viability of the two kinds of PTAs and show that the conditions under which FTAs are politically more palatable than CUs. This paper is forthcoming in the Journal of International Economics.
Immigration has become one of the most important political issue in the U.S. in recent years. Understanding how immigrant workers perform in the U.S. labor market is therefore an important area of research for economists. Past empirical evidence suggests that immigrant workers, while they tend to earn less than comparable native workers shortly after arriving to the U.S., tend to "assimilate" towards natives in their earnings the longer they are in the country, thus in part closing their earnings gap with native workers. Recent evidence, however, suggests that the rate of earnings assimilation has slowed dramatically for more recent immigrants.
In a working paper, Professor Hugh Cassidy investigates the assimilation patterns of immigrants through the lens of their job type. Specifically, he explores what job tasks immigrants perform, compared to native workers, and how these job tasks change over time. Immigrant workers tend to work in jobs that are more manually-intensive but less cognitively- and interpersonally-intensive. With longer duration in the country, earlier cohorts of immigrant workers tended to assimilate towards native workers in the types of job tasks they perform. However, more recent immigrants have shown a substantial slowdown in this task-related job assimilation, which echoes the results for earnings assimilation.
Most of the empirical work on the economic performance of immigrants focuses on adult immigrants - i.e. immigrants who arrive age 18 or later. In another working paper, Professor Cassidy explores how the earnings of childhood immigrants in the U.S. has changed over the past few decades. In 1990, immigrants who arrived to the U.S. as children had very similar earnings to native workers; however, by 2000, a large gap had emerged in earnings between the groups. This expansion appears to be largely due to the change in source country of immigrants. The earnings gap expanded further between 2000 and 2010, likely driven by the effects of the Great Recession harming immigrant workers more so than native workers.
Recent research projects by Yang-Ming Chang, professor of economics, include an examination of differences between the U.S. antitrust case and the E.U. antitrust case against Microsoft. In 2000, the U.S. Department of Justice called for Microsoft’s breakup for reasons that included the following: it monopolized the market for the operating systems; the integration of its browser, Internet Explorer(IE), into the Windows operating system was anti-competitive; its free distribution of IE was predatory; it engaged in anti-competitive contracts with personal computer manufactures and internet service providers; it impeded product innovation; and its competitive actions harmed consumers. But the U.S. government’s antitrust litigation against Microsoft was eventually overturned. In the E.U. Microsoft case, the European Community argued that Microsoft had abused market dominance in its operating systems by tying the sales of Windows Media Player or IE to Windows. Unlike the U.S. case, the E.U. was successful in ruling against Microsoft and the company was required to offer a clean version of Windows (without any browser or application software). Yang-Ming and his coauthor, Hung-Yi Chen, a Ph.D. in economics from Kansas State and currently a full professor at Soochow University, develop an economic model to capture the idiosyncratic characteristics of the operating system monopoly (i.e., Windows dominance) and of the oligopolistic market for browsers (IE, Netscape’s Navigator, or Opera). They examine the case of tying behavior in which Microsoft integrates IE into Windows to generate a bundled system good for sales, as compared to the no-tying case when Microsoft is required by the government to break into smaller entities. Their findings indicate that Microsoft’s tying enhances price competition in the browser market and the integration of IE with Windows as a system good is socially desirable. This is directly related to the fact that Windows is an essential component and the fact that it is run on more than ninety percents of all personal computers. Based on their model, they show that a Microsoft breakup stifles competition, hurts consumers, and is socially undesirable. The results of their study further indicate that the E.U. international antitrust intervention against Microsoft as a foreign exporter benefits the E.U. software producers at the expense of their computer users. The paper also addresses issues on international antitrust and protection of domestic industries in the E.U. case. Yang-Ming presented this paper on March 17, 2012, at the 10th Annual International Industrial Organization Conference, which was held at George Mason University in Arlington, Virginia.
It is widely believed that higher oil prices lead to inflation. Based on the experience of the 1970's and 1980's, most introductory macroeconomics textbooks teach students that a higher price of oil increases the cost of producing goods, which is then passed on to consumers in the form of higher prices. Research by Lance Bachmeier, associate professor of economics, and Inkyung Cha, visiting assistant professor of economics, has shown that is not the case. They examined the behavior of more than 100 "core" consumption goods, such as clothing, toys, and household appliances, and found that most prices either do not change or even fall when the price of oil rises. They find that the main reason oil shocks are no longer inflationary is that firms have adopted energy-efficient production technology. Firms use about half the energy to produce the same goods today as in 1970. Their paper was published in the September 2011 issue of the Journal of Money, Credit and Banking.