02.09.2026 • 24/2026
Launch of the European Real Estate Index (EREI): German housing prices continue to rise more slowly than in Europe
Growth in asking prices for German residential properties offered for sale has lagged the European EREI aggregate since spring 2025. This is shown by the new European Real Estate Index (EREI) presented today by the Halle Institute for Economic Research (IWH). This novel data service hinges on more than 43 million listings on online real estate platforms and provides monthly comparisons of residential asking prices and advertised rents across 1,154 European regions in near-real-time.
Michael Koetter
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Common Ownership and CEO Social Ties Across Portfolio Firms
Dennis Hutschenreiter, Qianshuo Liu
IWH Discussion Papers,
No. 9,
2026
Abstract
This paper examines whether common institutional ownership is associated with CEO connectedness across firms. We document that higher common ownership between two same-industry firms predicts a greater likelihood that a newly appointed CEO has preexisting social ties to the incumbent CEO of the peer firm. To address endogeneity, we use mergers among institutional investors in a stacked difference-in-differences design. In a hiring-firm-peer panel that carries connection status forward from the most recent appointment, exposure to a merger-induced common blockholder approximately doubles the probability that the pair is observed in a connected-CEO state. In a broader firm-pair panel, it increases the probability of CEO connections by 48.7%. We further document that gaining CEO connections through another firm’s CEO appointment is associated with improvements in peer firms’ returns on assets and Tobin’s Q, in both OLS and IV specifications. Peer firms that gain such a connection also experience positive abnormal returns around other firms’ CEO hiring announcements, corresponding to an average increase of $112.5 million in shareholder value. These performance patterns suggest that CEO connections may be valuable from a portfolio-level perspective. Consistent with this interpretation, the association between common ownership and CEO connections is concentrated among product-similar and organizationally complex firms and strengthens after the 2008–2009 financial crisis, when connections appear more valuable. Our findings point to CEO connection as a potential governance channel through which common institutional ownership is linked to firm outcomes, complementing prior work on executive compensation, shareholder voting, and board interlocks.
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Common Ownership, Tacit Know-How, and the Market for Technology
Dennis Hutschenreiter
IWH Discussion Papers,
No. 3,
2026
Abstract
Firms increasingly rely on markets for technology to acquire innovations developed outside their boundaries, yet acquiring intellectual property rights alone often does not guarantee successful implementation. Many technologies depend on tacit know-how that must be supplied by the provider after the transaction is completed. This paper examines whether common ownership between a technology provider and a potential adopter mitigates this implementation problem. I develop a model in which overlapping institutional investors cause the provider to partially internalize the adopter’s gains from successful implementation, strengthening incentives to transfer tacit know-how. This mechanism operates only when know-how is unverifiable – absent this friction, common ownership leaves matching and outcomes unchanged. Under moral hazard, the model predicts that common ownership increases the likelihood of technology transfer to a given adopter, that this effect is stronger when tacit know-how is more important, and that common ownership improves post-transfer outcomes conditional on adoption. I test these predictions using U.S. patent reassignments between publicly traded firms. Using within-deal variation across competing potential adopters and plausibly exogenous variation from passive index-fund holdings, I show that common ownership increases the likelihood that a firm acquires a technology, particularly when the transferred bundle is more tacit. Common ownership predicts stronger subsequent innovation and higher future firm value, especially when ownership overlap is concentrated among investors with stronger incentives to monitor the provider. These findings show how ownership structure shapes interfirm technology transfer by affecting not only who acquires a technology, but also how much value is created.
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Job Market Candidates
Job Market Candidates Dennis C. Hutschenreiter Dennis C. Hutschenreiter is a Postdoctoral Researcher in the Department of Financial Markets at the Halle Institute for Economic…
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Research Articles
Research Articles Explore cutting-edge research based on CompNet’s micro-aggregated firm-level data and related analytical tools. These articles cover empirical and theoretical…
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Halle Institute for Economic Research (IWH) – Member of the Leibniz Association
EREI-Update: Rents remain high in Spanish cities Pressure in the Spanish rental market made Prime Minister Sánchez call for early elections. The latest European Real Estate Index…
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From Rivals to Allies? CEO Connections in an Era of Common Ownership
Dennis Hutschenreiter, Qianshuo Liu
IWH Discussion Papers,
No. 7,
2025
Abstract
Institutional common ownership of firm pairs in the same industry increases the likelihood of a preexisting social connection among their CEOs. We establish this relationship using a quasi-natural experiment that exploits institutional mergers combined with firms’ hiring events and detailed information on CEO biographies. In addition, for peer firms, gaining a CEO connection from a hiring firm’s CEO appointment correlates with higher returns on assets, stock market returns, and decreasing product similarity between companies. We find evidence consistent with common owners allocating CEO connections to shape managerial decisionmaking and increase portfolio firms’ performance.
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14.05.2025 • 16/2025
Private ownership boosts hospital performance
New research by the Halle Institute for Economic Research (IWH) and ESMT Berlin shows that private equity (PE) acquisitions lead to substantial operational efficiency gains in hospitals, challenging common public concerns. The study reveals that hospitals acquired by PE firms significantly reduce costs and administrative staff without increasing closure rates or harming patient care.
Merih Sevilir
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From Shares to Machines: How Common Ownership Drives Automation
Joseph Emmens, Dennis Hutschenreiter, Stefano Manfredonia, Felix Noth, Tommaso Santini
IWH Discussion Papers,
No. 23,
2024
Abstract
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Trading away Incentives
Stefano Colonnello, Giuliano Curatola, Shuo Xia
IWH Discussion Papers,
No. 23,
2022
Abstract
Equity pay has been the primary component of managerial compensation packages at US public firms since the early 1990s. Using a comprehensive sample of top executives from 1992-2020, we estimate to what extent they trade firm equity held in their portfolios to neutralize increments in ownership due to annual equity pay. Executives accommodate ownership increases linked to options awards. Conversely, increases in stock holdings linked to option exercises and restricted stock grants are largely neutralized through comparable sales of unrestricted shares. Variation in stock trading responses across executives hardly appears to respond to diversification motives. From a theoretical standpoint, these results challenge (i) the common, generally implicit assumption that managers cannot undo their incentive packages, (ii) the standard modeling practice of treating different equity pay items homogeneously, and (iii) the often taken for granted crucial role of diversification motives in managers’ portfolio choices.
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