Vista hunting — Crater Lake National Park

Financial, Environmental, People & Innovation System Management

18. A. M. Petersen
    University digital media co-occurrence networks reveal structure and dynamics of brand visibility in the attention economy (pdf)
    Under review, (2024). Abstract As universities compete for visibility to attract student enrollment and build scientific reputation, the management of institution of higher education (IHE) brand has emerged as an important strategic endeavor. Yet our understanding of the factors that condition the structure and dynamics of brand stratification within regional IHE ecosystems is limited. Instead, our best approximation for brand equity derives from widespread IHE rankings, which lack contextual and relational features for understanding the patterns of engagement in the fast-moving attention economy, and in particular how institutional partnerships can generate brand equity by leveraging ecosystem network effects. To this end, here we develop a framework for measuring two dimensions of brand equity, namely visibility and association, according to the frequency of digital media articles featuring a university's official name. We demonstrate this approach for 29 universities in California and Texas based upon 2 million media articles published between 2000-2020, and validate our approach by correlating university digital media visibility with ARWU Shanghai rankings and freshman enrollment growth. As roughly 10% of the article sample features >1 university, longitudinal analysis of institutional co-occurrence reveals the extent to which brand association stratifies according to regional proximity, institutional specialization and prestige. Interestingly, despite the shared value generated from media co-visibility, the frequency of multi-university media articles has declined over time, which we attribute to paradigm shifts in media content production following the 2007-08 financial crisis and the COVID-19 infodemic, in addition to increased competitiveness of the attention economy. Topic classification of media article titles shows how specialized institutions may strategically manage their brand equity by aligning content production with dominant media topics to reinforce brand visibility with broader social, technological and environmental narratives.

17. A. M. Petersen, A. Montaño Ramirez
    Research university assortativity conditions the integration of regional innovation systems (pdf)
    Under review, (2024). Abstract Despite substantial policy efforts aimed at developing regional innovation systems (RIS), our understanding of institutional factors that promote synergy and integration at the regional scale is limited. To address this gap, we analyzed historical patterns of research co-production within and across California (CA) and Texas (TX), two RIS that together account for >5% of global scientific production. This predominance is largely attributed to the University of California and the University of Texas, two multi-campus university systems (MUS) that feature distinct configurations of institutional specialization. We exploit these differences to analyze four institutional assortativity channels that foster system-level synergies: institutional proximity, prestige, homophily, and specialization. Our results show that regional integration is mediated by the alignment of institutional specialization and moderated by institutional homophily, which thereby highlights MUS as valuable sources of institutional redundancy and variation that generate a large combinatorial space of potential multi-university research synergies. This configurational advantage is supported by results showing that research co-produced with a premier regional university and an international university feature a 21% (CA) and 25% (TX) citation premium. Hence, RIS administrators can extend productive capacity and global impact by identifying institutional synergies that optimize for both regional integrity and international competitiveness.

16. A. M. Petersen
    Shift in house price estimates during COVID-19 reveals effect of crisis on collective speculation (pdf)
    EPJ Data Science 13, 47 (2024). DOI:10.1140/epjds/s13688-024-00488-9 Abstract We exploit a timely city-level panel of individual house price estimates for both small and big real-estate markets in California USA to estimate the impact of COVID-19 on the housing market. Descriptive analysis of spot house price estimates, including contemporaneous price uncertainty and 30-day price change for individual properties listed on the online real-estate platform Zillow.com, together facilitate quantifying both the excess valuation and valuation confidence attributable to this global socio-economic shock. Our quasi-experimental pre-/post-COVID-19 design spans several years around 2020 and leverages contemporaneous price estimates of rental properties – i.e., real estate entering the habitation market, just not for purchase and hence free of speculation – as an appropriate counterfactual to properties listed for sale. Combining unit-level matching and difference-in-difference approaches, we estimate that properties listed for sale after the pandemic featured an excess monthly price growth of roughly 1 percentage points, corresponding to an excess annual price growth of roughly 12.7 percentage points, which accounts for more than half of the annual growth observed across those regions in 2021. Simultaneously, uncertainty in price estimates decreased, signaling the irrational confidence characteristic of prior asset bubbles. We explore how these two trends are related to market size, local market supply and borrowing costs, which altogether lend support for the counter-intuitive roles of uncertainty and interruptions in decision-making.

15. A. M. Petersen
    How much did pandemic uncertainty affect real-estate speculation? Evidence from on-market valuation of For-Sale versus Rental properties (pdf)
    In press, Applied Economics Letters (2024). DOI:10.1080/13504851.2024.2302898 Abstract We exploit a panel of Zillow Inc. property valuations to estimate the excess real-estate price growth observed in three California cities that is attributable to speculation triggered by the COVID-19 pandemic. Our research design leverages the counterfactual comparison of properties listed for sale to properties listed for rent, with the latter property class being available for habitation – just not for purchase – and thus neutral to price speculation. We implement a pre/post-2020 difference-in-difference estimation, which utilizes unit-level matching of otherwise similar sale and rental properties within a 1/2-mile radius of each other to compare differences in: (a) 1-month valuation changes; and (b) spot valuation uncertainties. Results indicate post-2020 property valuations in Merced and San Jose featured an excess annual price estimate growth of 22 and 14.8 percentage points, respectively, whereas the Fresno market does not feature statistically significant excess growth.

14. F. Arroyave, J. Jenkins, S. Shackelton, B. Jackson, A. M. Petersen
    Research alignment in the U.S. National Park System: Impact of transformative science policy on the supply and demand for scientific knowledge for protected area management (pdf)
    Journal of Environmental Management 357, 120699 (2024). DOI:10.1016/j.jenvman.2024.120699. Abstract The US national parks system encompasses diverse environmental and tourism management regimes, together governed by the 1916 Organic Act and its dual mandate of conservation and provision of public enjoyment. However, with the introduction of transformative science policy in the 2000’s, the mission scope has since expanded to promote overarching science-based objectives. Yet despite this paradigm shift instituting “science for parks, parks for science”, there is scant research exploring the impact of the national parks science policy on the provision of knowledge. We address this gap by developing a spatiotemporal framework for evaluating research alignment, here operationalized via quantifiable measures of supply and demand for scientific knowledge. Specifically, we apply a machine learning algorithm (Latent Dirichlet analysis) to a comprehensive park-specific text corpus (combining official needs statements -demand- and scientific research metadata -supply-) to define a joint topic space, which thereby facilitates quantifying the direction and degree of alignment at multiple levels. Results indicate an overall robust degree of research alignment, with misaligned topics tending to be over-researched (as opposed to over-demanded), which may be favorable to many parks, but is inefficient from the park system perspective. Results further indicate that the transformative science policy exacerbated the misalignment in mandated research domains. In light of these results, we argue for improved decision support mechanisms to achieve more timely alignment of research efforts towards distinctive park needs, thereby fostering convergent knowledge co- production and leveraging the full value of national parks as living laboratories.
    -How Scientific Research Can Inform Visitor and Environmental Management at National Parks, UC Merced Newsroom, Patty Guerra,
    

13. A. M. Petersen
    Megajournal mismanagement: Manuscript decision bias and anomalous editor activity at PLOS ONE (pdf)
    J. Informetrics 13, 100974 (2019). DOI:10.1016/j.joi.2019.100974 Abstract Since their emergence just a decade ago, nearly 2% of scientific research is now published by megajournals, representing a major industrial shift in the production of knowledge. Such high-throughput production stresses several aspects of the publication process, including the editorial oversight of peer-review. As the largest mega- journal, PLOS ONE has relied on a single-tier editorial board comprised of ∼7,000 active academics, who thereby face conflicts of interest relating to their dual roles as both producers and gatekeepers of peer-reviewed literature. While such conflicts of interest are also a factor for editorial boards of smaller journals, little is known about how the scalability of megajournals may introduce perverse incentives for editorial service. To address this issue, we analyzed the activity of PLOS ONE editors over the journal’s inaugural decade (2006-2015) and find highly variable activity levels. We then leverage this variation to model how editorial bias in the manuscript decision process relates to two editor-specific factors: repeated editor-author interactions and shifts in the rates of citations directed at editors – a form of citation remuneration that is analogue to self-citation. Our results indicate significantly stronger manuscript bias among a relatively small number of extremely active editors, who also feature relatively high self-citation rates coincident in the manuscripts they handle. These anomalous activity patterns are consistent with the perverse incentives and the temptations they offer at scale, which is the- oretically grounded in the "slippery-slope" evolution of apathy and misconduct in power-driven environments. By applying quantitative evaluation to the gatekeepers of scientific knowledge, we shed light on various ethics issues crucial to science policy – in particular, calling for more transparent and structured management of editor activity in megajournals that rely on active academics.
    -Personal biases speed up research publication: Megajournal editors under the microscope, Nature Index, Gemma Conroy
    -Analysis of highly prolific Plos One editors finds evidence for 'editor-author backscratching', Times Higher Education, Jack Grove
    -Editors secured citation bump, Science, Jeffrey Brainard

12. A. M. Petersen, R. K. Pan, F. Pammolli, S. Fortunato
    Methods to Account for Citation Inflation in Research Evaluation (pdf)
    Research Policy 48, 1855-1865 (2019). DOI:10.1016/j.respol.2019.04.009 Abstract Quantitative research evaluation requires measures that are transparent, simple, and free of disciplinary and temporal bias. We document and provide solution to a hitherto unaddressed temporal bias - citation inflation - which arises from the basic fact that scientific publication is steadily growing at roughly 4% per year. Because the total production of citations grows by a factor of 2 every 12 years, this means that the real value of a citation depends on when it was produced. As such, failing to convert nominal citation values into real citation values produces significant mis-measurement of scientific impact. To address this problem, we develop a citation deflator method, outline the steps to generalize and implement it using the Web of Science portal, and analyze a large set of researchers from biology and physics to demonstrate how two common evaluation metrics (total citations and h-index) can differ, by a remarkable amount, depending on whether the citations are deflated or not. In particular, our results show that the scientific impact of older generations is likely to be significantly underestimated when citations are not deflated, often by 100% or more of the nominal value. Thus, our study points to the need for a systemic overhaul of the counting methods used evaluating citation impact - especially in the case of researchers, journals, and institutions - which can span several decades and thus several doubling periods.
    

11. O. A. Doria Arrieta, F. Pammolli, A. M. Petersen
    Quantifying the negative impact of brain drain on the integration of European science (pdf)    (Supporting Information)
    Science Advances 3(4), e1602232 (2017). DOI:10.1126/sciadv.1602232 Abstract The 2004/2007 European Union (EU) enlargement by 12 member states offers a unique opportunity to quantify the impact of EU efforts to expand and integrate the scientific competitiveness of the European Research Area (ERA). We apply two causal estimation schemes to cross-border collaboration data extracted from millions of academic publications from 1996 to 2012, which are disaggregated across 14 subject areas and 32 European countries. Our results illustrate the unintended consequences following the 2004/2007 enlargement, namely, its negative impact on cross-border collaboration in science. First, we use the synthetic control method to show that levels of European cross-border collaboration would have been higher without EU enlargement, despite the 2004/2007 EU entrants gaining access to EU resources incentivizing cross-border integration. Second, we implement a difference-in-difference panel regression, incorporating official intra-European high-skilled mobility statistics, to identify migration imbalance - principally from entrant to incumbent EU member states - as a major factor underlying the divergence in cross-border integration between Western and Eastern Europe. These results challenge central tenets underlying ERA integration policies that unifying labor markets will increase the international competitiveness of the ERA, thereby calling attention to the need for effective home-return incentives and policies.
    -Study Identifies Effects of EU Expansion on Labor, Research, UC Merced Communications, Lorena Anderson
    -Europe's paradox: Why increased scientific mobility has not led to more international collaborations, Science, Erik Stokstad
    -Joining the European Union leads to less cross-border collaboration, Nature, Daniel Cressy
    -EU Expansion did not Increase Cross-Border Research, AAAS, Megan Jula
    -The EU Had a Scientific Collaboration Problem Long Before Brexit, Motherboard, Ben Sullivan

10. A. M. Petersen, M. Puliga
    High-skilled labour mobility in Europe before and after the 2004 enlargement (pdf)    (Supporting Information)
    Journal of the Royal Society Interface 14, 20170030 (2017). DOI:10.1098/rsif.2017.0030 Abstract The extent to which international high-skilled mobility channels are forming is a question of great importance in an increasingly global knowledge-based economy. One factor facilitating the growth of high-skilled labor markets is the standardization of certifiable degrees meriting international recognition. Within this context, we analyzed an extensive high-skilled mobility database comprising roughly 382,000 individuals from 5 broad profession groups (Medical, Education, Technical, Science & Engineering, and Business & Legal) over the period 1997-2014, using the 13-country expansion of the European Union (EU) to provide insight into labor market integration. We compare the periods before and after the 2004 enlargement, showing the emergence of a new East-West migration channel between the 13 mostly eastern EU entrants (E) and the rest of the western European countries (W). Indeed, we observe a net directional loss of human capital from E->W, representing 29% of the total mobility after 2004. Nevertheless, the counter-migration from W->E is 7% of the total mobility over the same period, signaling the emergence of brain circulation within the EU. Our analysis of the country-country mobility networks and the country-profession bipartite networks provides timely quantitative evidence for the convergent integration of the EU, and highlights the central role of the UK and Germany as high-skilled labor hubs.We conclude with two data-driven models to explore the structural dynamics of the mobility networks.First, we operationalize a redistribution model to explore the potential ramifications of Brexit, showing the extent to which a 'hard' Brexit, i.e. complete disintegration from the EU, may benefit the overall homogeneity of the European mobility network. Second, we use a panel regression model to explain empirical high-skilled mobility rates in terms of various economic `push-pull' factors, the results of which show that government expenditure on education, per-capita wealth, geographic proximity, and labor force size are significant attractive features of destination countries.
    -European mobility and the potential consequences of Brexit, The Royal Society, Ruth Milne
    -Cover of April 2017 issue of JRSI

9. A. M. Petersen, D. Rotolo, L. Leydesdorff
   A Triple Helix Model of Medical Innovation: Supply, Demand, and Technological Capabilities in terms of Medical Subject Headings (pdf)
   Research Policy 45(3), 666-681 (2016). DOI:10.1016/j.respol.2015.12.004 Abstract We develop a model of innovation that enables us to trace the interplay among three key dimensions of the innovation process: (i) demand of and (ii) supply for innovation, and (iii) technological capabilities available to generate innovation in the forms of products, processes, and services. Building on triple helix research, we use entropy statistics to elaborate an indicator of mutual information among these dimensions that can provide indication of reduction of uncertainty. To do so, we focus on the medical context, where uncertainty poses significant challenges to the governance of innovation. We use the Medical Subject Headings (MeSH) of MEDLINE/PubMed to identify publications classified within the categories "Diseases" (C),"Drugs and Chemicals" (D), "Analytic, Diagnostic, and Therapeutic Techniques and Equipment" (E) and use these as knowledge representations of demand, supply, and technological capabilities, respectively. Three case-studies of medical research areas are used as representative 'entry perspectives' of the medical innovation process. These are: (i) human papilloma virus, (ii) RNA interference, and (iii) magnetic resonance imaging. We find statistically significant periods of synergy among demand, supply, and technological capabilities (C-D-E) that point to three-dimensional interactions as a fundamental perspective for the understanding and governance of the uncertainty associated with medical innovation. Among the pairwise configurations in these contexts, the demand-technological capabilities (C-E) provided the strongest link, followed by the supply-demand (D-C) and the supply-technological capabilities (D-E) channels.

8. A. Morescalchi, F. Pammolli, O. Penner, A. M. Petersen, M. Riccaboni
   The evolution of networks of innovators within and across borders: Evidence from patent data (pdf)
   Research Policy 44(3), 651-668 (2015). DOI:10.1016/j.respol.2014.10.015 Abstract Recent studies on the geography of knowledge networks have documented a negative impact of physical distance and institutional borders upon research and development (R&D) collaborations. Though it is widely recognized that geographic constraints hamper the diffusion of knowledge, less attention has been devoted to the temporal evolution of these constraints. In this study we use data on patents filed with the European Patent Office (EPO) for 50 countries to analyze the impact of physical distance and country borders on inter-regional links in four different networks over the period 1988-2009: (1) co-inventorship, (2) patent citations, (3) inventor mobility and (4) the location of R&D laboratories. We find the constraint imposed by country borders and distance decreased until mid-1990s then started t o grow, particularly for distance. The intensity of European cross-country inventor collaborations increased at a higher pace than their non-European counterparts until 2004, with no significant relative progress afterwards. Moreover, when analyzing networks of geographical mobility, multinational R&D activities and patent citations we do not depict any substantial progress in European research integration aside from the influence of common global trends.
   

7. A. M. Petersen, S. Fortunato, R. K. Pan, K. Kaski, O. Penner, A. Rungi, M. Riccaboni, H. E. Stanley, F. Pammolli
   Reputation and Impact in Academic Careers (pdf)    (Supporting Information)
   Proceedings of the National Academy of Sciences USA 111, 15316-15321 (2014). DOI:10.1073/pnas.1323111111 Abstract Reputation is an important social construct in science, which enables informed quality assessments of both publications and careers of scientists in the absence of complete systemic information. However, the relation between reputation and career growth of an individual remains poorly understood, despite recent proliferation of quantitative research evaluation methods. Here we develop an original framework for measuring how a publication's citation rate \Delta c depends on the reputation of its central author i, in addition to its net citation count c. To estimate the strength of the reputation effect, we perform a longitudinal analysis on the careers of 450 highly-cited scientists, using the total citations C_i of each scientist as his/her reputation measure. We find a citation crossover cx which distinguishes the strength of the reputation effect. For publications with c < c_x, the author's reputation is found to dominate the annual citation rate. Hence, a new publication may gain a significant early advantage corresponding to roughly a 66% increase in the citation rate for each tenfold increase in C_i. However, the reputation effect becomes negligible for highly cited publications meaning that for c >= c_x the citation rate measures scientific impact more transparently. In addition we have developed a stochastic reputation model, which is found to reproduce numerous statistical observations for real careers, thus providing insight into the microscopic mechanisms underlying cumulative advantage in science.
   -Recognition: Build a reputation, Nature Jobs
   -Being a big name in science brings benefits, Nature
   -Researchers prefer citing researchers of good reputation, Phys.org
   -Scientists' reputations and citation rates, PNAS Highlight

6. A. Chessa, A. Morescalchi, F. Pammolli, O. Penner, A. M. Petersen, M. Riccaboni
   Is Europe Evolving Toward an Integrated Research Area? (pdf)
   Science 339, 650-651 (2013). DOI:10.1126/science.1227970 Abstract An integrated European Research Area (ERA) is a critical component for a more competitive and open European R&D system. However, the impact of EU-specific integration policies aimed at overcoming innovation barriers associated with national borders is not well understood. Here we analyze 2.4 x 10^6 patent applications filed with the European Patent Office (EPO) over the 25-year period 1986-2010 along with a sample of 2.6 x 10^5 records from the ISI Web of Science to quantitatively measure the role of borders in international R&D collaboration and mobility. From these data we construct five different networks for each year analyzed: (i) the patent co-inventor network, (ii) the publication co-author network, (iii) the co-applicant patent network, (iv) the patent citation network, and (v) the patent mobility network. We use methods from network science and econometrics to perform a comparative analysis across time and between EU and non-EU countries to determine the ``treatment effect'' resulting from EU integration policies. Using non-EU countries as a control set, we provide quantitative evidence that, despite decades of efforts to build a European Research Area, there has been little integration above global trends in patenting and publication. This analysis provides concrete evidence that Europe remains a collection of national innovation systems.
   - European Research: Still Fragmented After All These Years, AlphaGalileo Foundation
   - Europe still has a way to go to achieve true unity, Research Europe, Issue 359
   - Ricerca europea, l'integrazione ancora non c'e, Le Scienze (Scientific American, Italy)
   - Unione europea, ancora non cadono le frontiere della ricerca, Wired

5. A. M. Petersen, M. Riccaboni, H. E. Stanley, F. Pammolli.
   Persistence and Uncertainty in the Academic Career (pdf)
   Proceedings of the National Academy of Sciences USA 109, 5213 - 5218 (2012). DOI:10.1073/pnas.1121429109 Abstract Recent shifts in the business structure of universities and a bottleneck in the supply of tenure track positions are two issues that threaten to change the longstanding patronage system in academia. Understanding how institutional changes within academia may affect the overall potential of science requires a better quantitative understanding of how careers evolve over time. Since knowledge spillovers, cumulative advantage, and collaboration are distinctive features of the academic profession, the employment relationship should be designed to account for these factors. We quantify the impact of these factors in the production n_i(t) of a given scientist i by analyzing the longitudinal career data of 300 scientists and compare our results with 21,156 sports careers comprising a non-academic labor force. The increase in the typical size of scientific collaborations has led to the increasingly difficult task of allocating funding and assigning recognition. We use measures of the scientific collaboration radius, which can change dramatically over the course of a career, to provide insight into the role of collaboration in productio n efficiency. We introduce a model of proportional growth to provide insight into the complex relation between knowledge spillovers, competition, and uncertainty at the individual scale. Our model shows that high competition levels can make careers vulnerable to ``sudden death'' termination relatively early in the career as a result of negative production fluctuations and not necessarily due to lack of individual persistence.
   - Short-term contracts may hinder young scientists, PNAS Highlight
   

4. B. Podobnik, D. Horvatic, A. M. Petersen, B. Urosevic, H. E. Stanley.
   Bankruptcy risk model and empirical tests (pdf)
   Proceedings of the National Academy of Sciences USA 107, 18325 (2010). DOI:10.1073/pnas.1011942107 Abstract We compare bankrupt companies with non-bankrupt companies using Zipf ranking techniques to analyze the debt-to-assets leverage ratio R. Using the distribution of R for bankrupt versus non-bankrupt companies, we estimate the bankruptcy risk of an existing company conditional on its current R value and find that the probability of bankruptcy P(B) ~ R.
   - The relationship between bankruptcy and relative debt for U.S. companies , PNAS Highlight
   

3. A. M. Petersen, B. Podobnik, D. Horvatic, H. E. Stanley.
   Scale-invariant properties of public-debt growth (pdf)
   Europhysics Letters 90, 38006 (2010). DOI:10.1209/0295-5075/90/38006 Abstract Applying methods from macro-economic growth theory, we find 'convergence' in country debt-to-GDP leverage ratios over the last 30+ years.

2. A. M. Petersen, F. Wang, S. Havlin, H. E. Stanley.
   Quantitative law describing market dynamics before and after interest-rate change (pdf)
   Physical Review E 81, 066121 (2010). DOI:10.1103/PhysRevE.81.066121 Abstract We analyze the financial "earthquake" that occurs evey time the U.S. Federal Reserve makes an announcement to change the federal target interest rate, and estimate the magnitude of market `anticipation' and `surprise' using the fundamental relationship between the federal effective `overnight' interest rate and the 6-month Treasury Bill.
   - Bernanke Announcement Leaves Quake Like Aftershocks , Inside Science News Service

1. A. M. Petersen.
   Applications of Statistical Physics to the Social and Economic Sciences (pdf)
   PhD Thesis, Boston University (2011). Thesis Advisor: H. Eugene Stanley