Showing 21 - 30 of 84 Items
Date: 2013-11-01
Creator: Erik J. Nelson, Peter Kareiva, Mary Ruckelshaus, Katie Arkema, Gary, Geller, Evan Girvetz, Dave Goodrich, Virginia Matzek, Malin Pinsky
Access: Open access
- Climate change alters the functions of ecological systems. As a result, the provision of ecosystem services and the well-being of people that rely on these services are being modified. Climate models portend continued warming and more frequent extreme weather events across the US. Such weather-related disturbances will place a premium on the ecosystem services that people rely on. We discuss some of the observed and anticipated impacts of climate change on ecosystem service provision and livelihoods in the US. We also highlight promising adaptive measures. The challenge will be choosing which adaptive strategies to implement, given limited resources and time. We suggest using dynamic balance sheets or accounts of natural capital and natural assets to prioritize and evaluate national and regional adaptation strategies that involve ecosystem services. © The Ecological Society of America.
Date: 2013-03-10
Creator: Yao Tang, Daniel Shapiro, Miaojun Wang, Weiying Zhang
Access: Open access
- We investigate the degree to which corporate governance and ownership affects the innovation performance of firms in China with a particular focus on privately owned small and medium enterprises (SMEs). We hypothesize that (1) board-related governance measures will enhance innovation because they improve monitoring and provide access to necessary resources; (2) ownership concentration initially facilitates innovation because large shareholders are more likely to commit to the long-term nature of innovation, and have the incentive to monitor managers whose time horizon may be shorter; however we argue that these effects weaken as large shareholders becomes entrenched at higher levels of concentration; and (3) hiring an external CEO will enhance innovation both by ensuring professional management of the company, and by alleviating the entrenchment possibilities associated with large shareholders. These hypotheses are tested using a unique sample of 370 mostly private and relatively small Chinese firms in Zhejiang province, for the period 2004 to 2006. The results suggest that for this sample, corporate governance and ownership affect innovation activity when measured by patenting activity, but not when measured by new product sales.
Date: 2011-01-01
Creator: David J. Lewis, Andrew J. Plantinga, Erik Nelson, Stephen Polasky
Access: Open access
- Habitat loss is a primary cause of loss of biodiversity but conserving habitat for species presents challenges. Land parcels differ in their ability to produce returns for landowners and landowners may have private information about the value of the land to them. Land parcels also differ in the type and quality of habitat and the spatial pattern of land use across multiple landowners is important for determining the conservation value of parcels. This paper analyzes the relative efficiency of simple voluntary incentive-based policies in achieving biodiversity conservation objectives. This topic is important not just for biodiversity conservation but for any effort to provide a public good requiring coordination across multiple decision-makers who have some degree of private information. We develop a method that integrates spatially explicit data, an econometric model of private land-use decisions, landscape simulations, a biological model of biodiversity as a function of landscape pattern, and an algorithm that estimates the set of efficient solutions. These methods allow us to simulate landowner responses to policies, measure the consequences of these decisions for biodiversity conservation, and compare these outcomes to efficient outcomes to show the relative efficiency of various policy approaches. We find substantial differences in biodiversity conservation scores generated by simple voluntary incentive-based policies and efficient solutions. The performance of incentive-based policies is particularly poor at low levels of the conservation budget where spatial fragmentation of conserved parcels is a large concern. Performance can be improved by encouraging agglomeration of conserved habitat and by incorporating basic biological information, such as that on rare habitats, into the selection criteria. © 2010 Elsevier B.V.
Date: 2012-04-01
Creator: V. C. Radeloff, E. Nelson, A. J. Plantinga, D. J. Lewis, D., Helmers, J. J. Lawler, J. C. Withey, F. Beaudry, S. Martinuzzi
Access: Open access
- Land-use change significantly contributes to biodiversity loss, invasive species spread, changes in biogeochemical cycles, and the loss of ecosystem services. Planning for a sustainable future requires a thorough understanding of expected land use at the fine spatial scales relevant for modeling many ecological processes and at dimensions appropriate for regional or national-level policy making. Our goal was to construct and parameterize an econometric model of land-use change to project future land use to the year 2051 at a fine spatial scale across the conterminous United States under several alternative land-use policy scenarios. We parameterized the econometric model of land-use change with the National Resource Inventory (NRI) 1992 and 1997 land-use data for 844 000 sample points. Land-use transitions were estimated for five land-use classes (cropland, pasture, range, forest, and urban). We predicted land-use change under four scenarios: business-as-usual, afforestation, removal of agricultural subsidies, and increased urban rents. Our results for the business-as-usual scenario showed widespread changes in land use, affecting 36% of the land area of the conterminous United States, with large increases in urban land (79%) and forest (7%), and declines in cropland (\-16%) and pasture (\-13%). Areas with particularly high rates of land-use change included the larger Chicago area, parts of the Pacific Northwest, and the Central Valley of California. However, while land-use change was substantial, differences in results among the four scenarios were relatively minor. The only scenario that was markedly different was the afforestation scenario, which resulted in an increase of forest area that was twice as high as the business-as-usual scenario. Land-use policies can affect trends, but only so much. The basic economic and demographic factors shaping land-use changes in the United States are powerful, and even fairly dramatic policy changes, showed only moderate deviations from the business-as-usual scenario. Given the magnitude of predicted land-use change, any attempts to identify a sustainable future or to predict the effects of climate change will have to take likely land-use changes into account. Econometric models that can simulate land-use change for broad areas with fine resolution are necessary to predict trends in ecosystem service provision and biodiversity persistence. © 2012 by the Ecological Society of America.
Date: 2021-12-01
Creator: Gonca Senel, Mark L.J. Wright
Access: Open access
- Recent work has found that countries with older populations face steeper yield curves and issue shorter maturity debt than do younger countries. We reexamine these findings using a new database of public debt maturity and yields for OECD countries. We first show that the behavior of eurozone countries in the pre-euro period drives these results. Next, including more recent data from the post-euro period, we show that the relationship between population age, maturity, and yield curve slopes disappears. This finding is robust to excluding high-credit-risk countries. Last, we show that these patterns reemerge after the European debt crisis, suggesting that eurozone capital markets have resegmented.
Date: 2019-04-01
Creator: Daniel F. Stone
Access: Open access
- Extreme partisan animosity has been on the rise in the US and is prevalent around the world. This hostility is typically attributed to social group identity, motivated reasoning, or a combination thereof. In this paper, I empirically examine a novel contributing factor: the “unmotivated” cognitive bias of overprecision (overconfidence in precision of beliefs). Overprecision could cause partisan hostility indirectly via inflated confidence in one's own ideology, partisan identity, or perceptions of social distance between the parties. Overprecision could also cause this hostility directly by causing excessively strong inferences from observed information that is either skewed against the out-party or simply misunderstood. Using a nationally representative sample, I find consistent support for direct effects of overprecision and mixed support for indirect effects. The point estimates imply a one standard deviation increase in a respondent's overprecision predicts as much as a 0.71 standard deviation decline in relative out-party favorability.
Date: 2020-09-01
Creator: Marcel Garz, Jil Sörensen, Daniel F. Stone
Access: Open access
- This study investigates the effects of variation in “congeniality” of news on Facebook user engagement (likes, shares, and comments). We compile an original data set of Facebook posts by 84 German news outlets on politicians that were investigated for criminal offenses from January 2012 to June 2017. We also construct an index of each outlet's media slant by comparing the language of the outlet with that of the main political parties, which allows us to measure the congeniality of the posts. We find that user engagement with congenial posts is higher than with uncongenial ones, especially in terms of likes. The within-outlet, within-topic design allows us to infer that the greater engagement with congenial news is likely driven by psychological and social factors, rather than a desire for accurate or otherwise instrumental information.
Date: 2023-01-01
Creator: Anna G Constantine
Access: Open access
- Special Purpose Acquisition Companies marked a restructuring of the often-fraudulent 1980s blank check company, an entity gathering funds to merge or acquire another business entity. Based on the Special Purpose Acquisition Company structure, “the stock price should be greater than or equal to the pro-rata trust value, discounted from the SPAC’s expiration date, at all times prior to the shareholder vote date.” In this study, I research the “no target” phase of the Special Purpose Acquisition Company’s lifecycle to evaluate whether there is a difference between their trust value and their market capitalization. Based on previous research, we know that there is a discount to trust value prior to 2009; however, I postulate the decoupling of the SPAC merger approval vote and the vote for investors to redeem may eliminate this discount. Using a first difference regression to establish the premium to the average trust value of 1,057 Special Purpose Acquisition Companies traded between 2005 and 2022, we find that both the period before 2010 and after 2010 trades at a negative premium, or discount. Because the decoupling of the merger vote and the redemption vote did not eliminate the negative premium to trust value, I postulate that the structure of SPAC redemptions, modeled as a call option with decaying time value, may be responsible for this mispricing. I also draw opportunities for future research to investigate if the embedding of a call option into the SPAC redemption structure discourages shareholders from desiring merger outcomes early in the SPAC lifecycle.

- Restriction End Date: 2029-06-01
Date: 2024-01-01
Creator: Tingjun Huang
Access: Access restricted to the Bowdoin Community
Date: 2017-05-26
Creator: Nicole Sadowsky, Erik Nelson
Access: Open access
- Since 2011, the private ride-hailing companies Uber and Lyft have expanded into more and more US cities. We use regression discontinuity design to examine the impact of Uber and Lyft’s entry on public transportation use in the US’ largest urban areas. In most cases, entry into cities by the two ride-hailing companies was staggered: Uber entered first followed some months later by Lyft. We find that public transportation use increased in an urban area, all else equal, immediately following the first entry. However, we find that the spike in public transportation use after first entry disappeared following the entry of the second company. In fact there is some evidence that monthly public transportation ridership levels fell below their pre-first entry levels. In other words, the joint presence of the two major private ride-hailing services transformed ride-hailing services from a public transportation complement to a public transportation substitute, at least in the studied urban areas. We speculate that the first entrant complemented public transportation use for some in an urban area by solving the “last-mile” problem and by providing a potentially safer option at night when public transportation service has been reduced. However, we speculate the second entrant is likely to have spurred price competition in the urban area’s ride-hailing duopoly market and an increase in ride-hailing car supply. This competitive effect could have tipped the scales, making an entire trip with a ride-hailing service more cost-effective and convenient than splitting a trip between a ride-share company and public transportation.