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Existing methods for detecting algorithmic pricing rely on high-frequency data with sub-daily timestamps, yet academic researchers and competition authorities typically have access only to daily price snapshots. This paper develops a heuristic that identifies likely algorithmic pricers in such low-resolution data by combining two standardised metrics: the Average Rate of Price Changes (ARPC), capturing the frequency of price adjustments, and a Market Presence Ratio (MPR), capturing sustained retailer engagement. Requiring both metrics to exceed a threshold reduces false positives from promotional sellers and transient market participants. We apply the heuristic to a dataset of 10,365 unique retailer-category observations from the PriceSpy price comparison platform, covering seven national markets and 16 product categories over an 18-month period (July 2021–December 2022). Our results show that algorithmic pricing is prevalent across markets, with algorithmic pricers present in all 16 categories in the United Kingdom and in all seven countries for six categories. Prevalence is notably higher in consumer electronics than in household appliances. As a lower-bound estimate, approximately 4.5% of retailers are classified as algorithmic pricers at our baseline threshold. The heuristic provides a practical screening tool for competition authorities investigating algorithmic pricing adoption using commercially available data.

This study introduces a heuristic for detecting retailers utilizing algorithmic pricing in low-resolution price data. By using metrics that account for both the frequency of price adjustments and the degree of retailer market presence, we improve upon existing methods for detecting algorithmic pricing retailers. Our results show that there are algorithmic pricers active in all 16 product categories under study in the UK, while only seven out of the 16 categories have at least one algorithmic pricer in Denmark. As for categories, algorithmic pricers are more common in the consumer electronics categories than in household appliances. They are least common in the Cookers category, where only the UK has at least one algorithmic pricer in the market. On the other hand, for the Headphones, Mobile phones, PC-games, Portable speakers, Tablets and Xbox games categories, algorithmic pricers are present in all seven national markets under study. As such, algorithmic pricing is nowadays common in many national and product markets. 

If online retail markets are integrated, in that cost shocks in one country also affect pricing in other countries, asymmetric shocks to any one country in the region will spill over to neighboring countries as well. Using web-scraped product-level prices from a group of retail firms selling identical products in at least two of the four Nordic markets under study, we investigate if national markets are segmented at the borders. Contrary to previous studies, we use differences in product characteristics to divide the data into products that are easily transported across borders and those that are not. At the extreme end of the transportability spectrum, we investigate market integration for four types of games for computers or game consoles that are delivered via downloads, where the cross-border transaction costs should be close to zero. Our results show that markets for product categories where cross-border transaction costs are high are also segmented at the border, while markets for product categories that can easily be traded and transported between countries are not. As such, cross-border transaction costs still matter for market segmentation, but only for the sub-set of products where such costs are high.

Syftet med vårt projekt har varit att studera hur en ökad internationalisering av handeln som bransch, med ökade internationella prisjämförelser och ökad internationell e-handel, påverkar e-handlares prissättning och lokala marknaders känslighet för asymmetriska chocker. 

If online retail markets are integrated, in that cost shocks in one country also affect pricing in other countries, asymmetric shocks to any one country in the region will spill over to neighboring countries as well. Using web-scraped productlevel prices from a group of retail firms selling identical products in at least two of the four Nordic markets under study, we investigate if national markets are segmented at the borders. Contrary to previous studies, we use differences in product characteristics to divide the data into products that are easily transported across borders and those that are not. At the extreme end of the transportability spectrum, we investigate market integration for four types of games for computers or game consoles that are delivered via downloads, where the cross-border transaction costs should be close to zero. Our results show that markets for product categories where cross-border transaction costs are high are also segmented at the border, while markets for product categories that can easily be traded andtransported between countries are not. We find an even higher level of market integration for games delivered via downloads than for the same games sold through traditional channels. As such, cross-border transaction costs still matter for market segmentation, but only for the sub-set of products where such costs are high. 

A substantial literature indicates that competition on price comparison websites is fierce, leading to lower prices for products sold. As such, we want to answer the key research question: Why do firms compete on price comparison websites? Based on theory, we suggest that participation in these marketplaces leads to increased productivity, i.e., output increases when holding constant the level of inputs used. This, in turn, leads to increased profits, motivating firms to enter price comparison websites despite fierce competition. To find out if theory holds, we empirically investigate how firm entry into a price comparison website affects firm productivity, profits, and wages. Empirically investigating the impact of PriceSpy market participation on productivity, profits, and wages is not easy since firms are free to select whether and when to enter or exit the PriceSpy marketplace, and we use a two-step procedure to address this problem. In the first step, we control for differences in observables between entering firms and potential control-group firms. Then, in a second step, we use a within-firm difference-in-difference estimator on the matched data to investigate how entry into the PriceSpy marketplace affects output while holding inputs constant. Our results indicate that for the full sample of firms, PriceSpy participation increases output by almost 12% when holding the level of inputs constant. Also, an investigation of who gains from the increased productivity shows that, for entering firms, operating profits increase by 9% and gross wages by 14% when studying the full sample of firms. That labor gains more from PriceSpy participation is even clearer when studying the impact on wholesale and retail firms separately. For those firms, wages increased by 16–17% after entry, while no statistically significant impact was found regarding operating profits.

This paper examines price elasticities on a price comparison website and if there is a discontinuity in demand for retailers having the lowest price or products having the highest consumer rating. Previous research is extended upon, with a larger, more recent, and more varied dataset, with retailers and products followed over a longer period. It is found that there is a statistically significant positive discontinuity in demand for retailers offering the lowest price. However, the results also show that the magnitude of the effect can vary substantially between product categories. The increase in demand ranges from 58% to 154%, with an average effect of 92%. The results pertaining to consumer ratings are found to be inconclusive. The importance for retailers of maintaining the lowest price therefore remains strong, while consumer ratings seem to have less of an impact on consumer demand.

Price comparison websites, where consumers can compare prices at a search cost that is close to zero, have become increasingly common around the world. Using daily information on prices, click-throughs, and the number of retailers for a sample of consumer electronics and durable goods over a period of 62 months, we investigate the effects of the increased use of the Swedish price comparison website PriceSpy on prices and price dispersion. We find that increased use by consumers created potential savings of 290 million SEK in 2016, while increased use by retailers created potential savings of approximately 2.9 billion SEK. Reduced prices due to increased use of the price comparison website thus resulted in total potential consumer savings of nearly 3.2 billion SEK (289 million EUR) for the year 2016 alone. Price comparison websites thus place downward pressure on prices, thereby increasing economic efficiency. We also find that the increased use of the price comparison website by retailers resulted in increased price dispersion, while the effect of more consumers using the website was mixed.

Online information sharing by firms has created an unprecedented amount of data to analyze by researchers. While conclusions from research should be drawn with basis in sound theory, there has also emerged a need to supplement these theoretical considerations with advanced data collection, storage and analysis as well as reporting to decisionmakers. As such, the emergence of the research field of microdata analysis has given aid in the process of gathering large quantities of data and managing databases, analyzing said data with knowledge in advanced areas, e.g., statistical inference, machine learning, artificial intelligence and the like, and presenting the results for decisionmakers and stakeholders in a clear, coherent way while also stating economic consequences to enable decision-making. This dissertation consists of five individual papers contributing to this field of research, and in the process answering a set of questions related to voluntary information sharing, retail pricing, and firm performance.

In the first paper, a large-scale data collection of corporate social responsibility reports was coupled with state-of-the-art topic modelling analysis to answer the question who the intended users of these reports are, and the results show that the shareholder perspective is more prominent rather than the stakeholder perspective. The second paper empirically shows the value of having lowest price or highest ratings on a price comparison website, with the former being found to have a profound impact on demand, while the effect of the latter is more unclear. The third paper relies on time series clustering analysis to test if intertemporal price discrimination is the cause of remaining price dispersion in low search cost markets. The empirical evidence rejects an established theory of explaining price dispersion in a wide range of markets characterized by low search costs. The fourth paper provides an investigation into how the increased use of a price comparison website affect pricing. It is found that an increased use of the platform and number of retailers entering lead to a reduction in average prices with substantial consumer savings as the general outcome. Following the results of the third paper, a more likely model to explain the persistent price dispersion in low search cost markets is also presented. The fifth and final paper combines two datasets with rigorous statistical analysis to answer why firms compete on price comparison websites, despite the threat of increased competition and reductions in prices. The results show that retailers competing on price comparison websites increase their productivity which creates increased profits that are shared between shareholders and employees. The different types of information sharing studied in this thesis is thus found to have profound impact on consumers, firms and society at large.