Trends and Determinants of US Farmland Values Since 1910: Evidence from the Iowa Land Value Survey

Valued at 2.31 trillion US dollars in 2016, farm real estate (land and structures) accounted for 85% of total US farm assets; in addition, farm real estate also represents the largest single item in a typical farmer’s investment portfolio. As a result, changes in its values have been a perennial interest to policy-makers, farmers, researchers and investors alike. Focusing on Iowa, a Midwestern state at the heart of the Corn Belt, and using annual data since 1950 from the Iowa Land Value Survey, this article analyses what drives the changes in land values in Iowa and across the Midwest over time from 1910 to 2016, assesses the return and profitability of farmland as an alternative of investment, and also compares the current downturn in US farmland values with the 1920s and 1980s farm crises. There have been three major ‘golden’ eras in US modern agriculture over the last 100 years: 1910 to 1920, 1973 to 1981, and the most recently from 2003 to 2013. The first two ended in a farm crisis, and many worry the third one is in the making. While the declining farm income and land values are alarming, this article argues that it is very unlikely that we will see a replay of 1980s farm crisis or a sudden collapse of US farm sector. The significant farm income accumulation during 2003–13, the stronger government safety net, and historically low interest rates should help agricultural producers withstand the downturn pressures. This article also compares the relative return of investment in Iowa farmland and S&P 500 by taking both the income generation and capital gains of these two assets into consideration. The results show that the investment timing and holding period are key in determining the relative return of the investment

Treatment outcomes from the largest antiretroviral treatment program in Myanmar (Burma): a cohort analysis of retention after scale-up.

Article approval pendingAntiretroviral treatment (ART) coverage in Myanmar is well below average. This study describes retention and baseline predictors of prognosis from the largest ART program in the country

HPC-driven computational reproducibility

Reproducibility of results is a cornerstone of the scientific method. Scientific computing encounters two challenges when aiming for this goal. Firstly, reproducibility should not depend on details of the runtime environment, such as the compiler version or computing environment, so results are verifiable by third-parties. Secondly, different versions of software code executed in the same runtime environment should produce consistent numerical results for physical quantities. In this manuscript, we test the feasibility of reproducing scientific results obtained using the IllinoisGRMHD code that is part of an open-source community software for simulation in relativistic astrophysics, the Einstein Toolkit. We verify that numerical results of simulating a single isolated neutron star with IllinoisGRMHD can be reproduced, and compare them to results reported by the code authors in 2015. We use two different supercomputers: Expanse at SDSC, and Stampede2 at TACC. By compiling the source code archived along with the paper on both Expanse and Stampede2, we find that IllinoisGRMHD reproduces results published in its announcement paper up to errors comparable to round-off level changes in initial data parameters. We also verify that a current version of IlliinoisGRMHD reproduces these results once we account for bug fixes which has occurred since the original publicationComment: 22 pages, 6 figures, submitted to Classical and Quantum Gravit

Co-benefits of global, domestic, and sectoral greenhouse gas mitigation for US air quality and human health in 2050

Policies to reduce greenhouse gas (GHG) emissions can bring ancillary benefits of improved air quality and reduced premature mortality, in addition to slowing climate change. Here we study the co-benefits of global and domestic GHG mitigation on US air quality and human health in 2050 at fine resolution using dynamical downscaling, and quantify for the first time the co-benefits from foreign GHG mitigation. Relative to a reference scenario, global GHG reductions in RCP4.5 avoid 16000 PM2.5-related all-cause deaths yr-1 (90% confidence interval, 11700-20300), and 8000 (3600-12400) O3-related respiratory deaths yr-1 in the US in 2050. Foreign GHG mitigation avoids 15% and 62% of PM2.5- and O3-related total avoided deaths, highlighting the importance of foreign GHG mitigation on US human health benefits. GHG mitigation in the US residential sector brings the largest co-benefits for PM2.5-related deaths (21% of total domestic co-benefits), and industry for O3 (17%). Monetized benefits, for avoided deaths from ozone, PM2.5, and heat stress from a related study, are $148 ($96-201) per ton CO2 at high valuation and $49 ($32-67) at low valuation, of which 36% are from foreign GHG reductions. These benefits likely exceed the marginal cost of GHG reductions in 2050. The US gains significantly greatermore » co-benefits when coordinating GHG reductions with foreign countries. Similarly, previous studies estimating co-benefits locally or regionally may greatly underestimate the full co-benefits of coordinated global actions.« les

Co-benefits of global and regional greenhouse gas mitigation for US air quality in 2050

Policies to mitigate greenhouse gas (GHG) emissions will not only slow climate change but can also have ancillary benefits of improved air quality. Here we examine the co-benefits of both global and regional GHG mitigation for US air quality in 2050 at fine resolution, using dynamical downscaling methods, building on a previous global co-benefits study (West et al., 2013). The co-benefits for US air quality are quantified via two mechanisms: through reductions in co-emitted air pollutants from the same sources and by slowing climate change and its influence on air quality, following West et al. (2013). Additionally, we separate the total co-benefits into contributions from domestic GHG mitigation vs. mitigation in foreign countries. We use the Weather Research and Forecasting (WRF) model to dynamically downscale future global climate to the regional scale and the Sparse Matrix Operator Kernel Emissions (SMOKE) program to directly process global anthropogenic emissions to the regional domain, and we provide dynamical boundary conditions from global simulations to the regional Community Multi-scale Air Quality (CMAQ) model. The total co-benefits of global GHG mitigation from the RCP4.5 scenario compared with its reference are estimated to be higher in the eastern US (ranging from 0.6 to 1.0 µg m−3) than the west (0–0.4 µg m−3) for fine particulate matter (PM2.5), with an average of 0.47 µg m−3 over the US; for O3, the total co-benefits are more uniform at 2–5 ppb, with a US average of 3.55 ppb. Comparing the two mechanisms of co-benefits, we find that reductions in co-emitted air pollutants have a much greater influence on both PM2.5 (96 % of the total co-benefits) and O3 (89 % of the total) than the second co-benefits mechanism via slowing climate change, consistent with West et al. (2013). GHG mitigation from foreign countries contributes more to the US O3 reduction (76 % of the total) than that from domestic GHG mitigation only (24 %), highlighting the importance of global methane reductions and the intercontinental transport of air pollutants. For PM2.5, the benefits of domestic GHG control are greater (74 % of total). Since foreign contributions to co-benefits can be substantial, with foreign O3 benefits much larger than those from domestic reductions, previous studies that focus on local or regional co-benefits may greatly underestimate the total co-benefits of global GHG reductions. We conclude that the US can gain significantly greater domestic air quality co-benefits by engaging with other nations to control GHGs.</html

Belief bias and representation in assessing the Bayesian rationality of others

People often assess the reasonableness of another person’s judgments. When doing so, the evaluator should set aside knowledge that would not have been available to the evaluatee to assess whether the evaluatee made a reasonable decision, given the available information. But under what circumstances does the evaluator set aside information? On the one hand, if the evaluator fails to set aside prior information, not available to the evaluatee, they exhibit belief bias. But on the other hand, when Bayesian inference is called for, the evaluator should generally incorporate prior knowledge about relevant probabilities in decision making. The present research integrated these two perspectives in two experiments. Participants were asked to take the perspective of a fictitious evaluatee and to evaluate the reasonableness of the evaluatee’s decision. The participant was privy to information that the fictitious evaluatee did not have. Specifically, the participant knew whether the evaluatee’s decision judgment was factually correct. Participants’ judgments were biased (Experiments 1 and 2) by the factuality of the conclusion as they assessed the evaluatee’s reasonableness. We also found that the format of information presentation (Experiment 2) influenced the degree to which participants’ reasonableness ratings were responsive to the evaluatee’s Bayesian rationality. Specifically, responsivity was greater when the information was presented in an icon-based, graphical, natural-frequency format than when presented in either a numerical natural-frequency format or a probability format. We interpreted the effects of format to suggest that graphical presentation can help organize information into nested sets, which in turn enhances Bayesian rationality

Incidence, risk factors and causes of death in an HIV care programme with a large proportion of injecting drug users.

Objectives  To identify factors influencing mortality in an HIV programme providing care to large numbers of injecting drug users (IDUs) and patients co-infected with hepatitis C (HCV). Methods  A longitudinal analysis of monitoring data from HIV-infected adults who started antiretroviral therapy (ART) between 2003 and 2009 was performed. Mortality and programme attrition rates within 2 years of ART initiation were estimated. Associations with individual-level factors were assessed with multivariable Cox and piece-wise Cox regression. Results  A total of 1671 person-years of follow-up from 1014 individuals was analysed. Thirty-four percent of patients were women and 33% were current or ex-IDUs. 36.2% of patients (90.8% of IDUs) were co-infected with HCV. Two-year all-cause mortality rate was 5.4 per 100 person-years (95% CI, 4.4-6.7). Most HIV-related deaths occurred within 6 months of ART start (36, 67.9%), but only 5 (25.0%) non-HIV-related deaths were recorded during this period. Mortality was higher in older patients (HR = 2.50; 95% CI, 1.42-4.40 for ≥40 compared to 15-29 years), and in those with initial BMI < 18.5 kg/m(2) (HR = 3.38; 95% CI, 1.82-5.32), poor adherence to treatment (HR = 5.13; 95% CI, 2.47-10.65 during the second year of therapy), or low initial CD4 cell count (HR = 4.55; 95% CI, 1.54-13.41 for <100 compared to ≥100 cells/μl). Risk of death was not associated with IDU status (P = 0.38). Conclusion  Increased mortality was associated with late presentation of patients. In this programme, death rates were similar regardless of injection drug exposure, supporting the notion that satisfactory treatment outcomes can be achieved when comprehensive care is provided to these patients