Evaluating wind-following and ecosystem services for hydroelectric dams in PJM

Hydropower can provide inexpensive, flexible fill-in power to compensate for intermittent renewable generation. Policies for hydropower dams maintain multiple services beyond electric generation, including environmental protection, flood control and recreation. We model the decision of a hydroelectric generator to shift some of its power production capacity away from the day-ahead energy market into a “wind-following” service to smooth the intermittent production of wind turbines. Offering such a service imposes both private and social opportunity costs. Since fluctuations in wind energy output are not perfectly correlated with day-ahead energy prices, a wind-following service will necessarily affect generator revenues. Seasonal wind patterns produce conflicts with the goal of managing rivers for “ecosystem services”—the maintenance or enhancement of downstream ecosystems. We illustrate our decision model using the Kerr Dam in PJM’s territory in North Carolina. We simulate the operation of Kerr Dam over a three-year period that features hydrologic variability from normal water years to extreme drought conditions. We use an optimization framework to estimate reservation prices for Kerr Dam offering wind-following services in the PJM market. Wind-following may be profitable for Kerr Dam at low capacity levels during some time periods if ecosystems services are neglected and if side payments, or reserves-type payments, are provided. Wind-following with ecosystem services yields revenue losses that typically cannot be recovered with reserves market payments. Water release patterns are inconsistent with ecosystem-services goals when Kerr Dam dedicates significant capacity to wind-following, particularly in drought years.     

History’s a curse: leapfrogging, growth breaks and growth reversals under international borrowing without commitment

A simple open-economy AK model with collateral constraints accounts for growth breaks and growth-reversal episodes, during which countries face abrupt changes in their growth rate that may lead to either growth miracles or growth disasters. Absent commitment to investment by the borrowing country, imperfect contract enforcement leads to an informational lag such that the debt contracted upon today depends upon the past stock of capital. The no-commitment delay originates a history effect by which the richer a country has been in the past, the more it can borrow today. For (arbitrarily) small delays, the history effect offsets the growth benefits from international borrowing and dampens growth, and it leads to both leapfrogging in long-run levels and growth breaks. When large enough, the history effect originates growth reversals and we connect the latter to leapfrogging. Finally, we argue that the model accords with the reported evidence on changes in the growth rate at break dates. We also provide examples showing that leapfrogging and growth reversals may coexist, so that currently poor but fast-growing countries experiencing sharp growth reversals may end up, in the long-run, significantly richer than currently rich but declining countries.     

Individual versus Village Lending: Evidence from Montenegro

This paper analyzes differences in loan performance across two Montenegrin microfinance institutions with different lending techniques using a sample of individuals borrowing from both institutions. We make use of administrative data from both institutions over the period 2004–2013. While one institution relies on village associations for screening and monitoring of borrowers, the other institution uses the individual liability approach. We find that the likelihood to go into arrears is higher for the institution with a strictly individual lending technique, while the likelihood of going into arrears over 30 days is higher for the institution working with village associations. These results are robust to a variety of additional tests, including different definitions of arrears and subsamples. Our findings suggest that the institution using an individual lending technique provides certain flexibility to its clients, while the village‐based microfinance institution might face more strategic default behavior. We provide evidence that once a borrower is in arrears, (s)he is more likely to stay in arrears for more than 30 days in branches with a higher share of borrowers in arrears and in the village‐based lender. Our findings provide evidence that a village‐ or group‐based lending technique is not necessarily superior to the individual lending technique in terms of loan performance.     

Did Hayek have a monetary theory of business cycles?

Joseph Schumpeter, a careful reader of Hayek, categorized Hayek??s theory of economic cycles as non-monetary. Almost every other source, including Hayek himself, categorized the theory as monetary. The issue turns on the concept of causality being used. The question of what causality concept to apply to complex phenomena has substantive implications for economic theory. A simple concept of causality, appropriate to the study of some physical phenomena, will mislead when applied to complex phenomena. We provide examples of errors in analysis that follow from the wrong choice of a causal paradigm.     

An efficient nonparametric estimator for models with nonlinear dependence

We provide a convenient econometric framework for the analysis of nonlinear dependence in financial applications. We introduce models with constrained nonparametric dependence, which specify the conditional distribution or the copula in terms of a one-dimensional functional parameter. Our approach is intermediate between standard parametric specifications (which are in general too restrictive) and the fully unrestricted approach (which suffers from the curse of dimensionality). We introduce a nonparametric estimator defined by minimizing a chi-square distance between the constrained densities in the family and an unconstrained kernel estimator of the density. We derive the nonparametric efficiency bound for linear forms and show that the minimum chi-square estimator is nonparametrically efficient for linear forms.     

In at the deep end: Conducting processual research on organisational change

This article provides a series of reflections on the practice of carrying out processual research on organisational change. At a broad level, some of the main tasks associated with conducting company case studies are described and the benefits of this approach for dealing with complex change data are outlined. At a more specific level, the article addresses three main areas tied to the actual “doing” of processual research. First, the notion of tacit knowledge and “getting your hands dirty” by engaging in ongoing in-depth fieldwork. Second, the design and implementation of a longitudinal case study research programme. Third, the advantages and concerns of combining a range of different data collecting techniques in carrying out processual studies. Overall, the main intention is to provide some useful reflections and practical insights, as well as providing something of the flavour of carrying out this type of research.     

Measuring the Level and Inequality of Wealth: An Application to China

We construct and compare three distinct measures of household asset wealth that complement traditional income‐ or expenditure‐based measures of socioeconomic status. We apply these measures to longitudinal household survey data from China and demonstrate that household asset wealth has been increasing over time, a theme consistent with many previous studies on the process of development in China. Unlike other studies that have shown rising income inequality over time, however, we show that asset wealth inequality has actually been declining in recent years, indicating widespread participation in the benefits of economic reforms. Furthermore, the evolution in the cumulative distribution of household welfare is such that social welfare has been increasing with the passage of time, despite rising inequality in the early years of the survey.     

Mr. Market's Mind: Finance's Hard Problem

The market as a mind is the implicit premise in any discussion on whether the market is rational or not. Still, its implications, in terms of ontology and epistemology, are hardly understood. In particular, this paper defines the market's version of the mind-body problem and labels it as finance's “hard” problem. Its denial by modern finance causes this dominant paradigm to fail in dealing with reality in general and to produce incomplete investment knowledge in particular. Finally, as part of facing up to this problem, this paper offers a glimpse at a practical approach which may enrich investment research.     

Cost-effectiveness of rivaroxaban compared with enoxaparin plus a vitamin K antagonist for the treatment of venous thromboembolism

Background:

Venous thromboembolism (VTE), comprised of deep vein thrombosis (DVT) and pulmonary embolism (PE), is commonly treated with a low-molecular-weight heparin such as enoxaparin plus a vitamin K antagonist (VKA) to prevent recurrence. Administration of enoxaparin?+?VKA is hampered by complexities of laboratory monitoring and frequent dose adjustments. Rivaroxaban, an orally administered anticoagulant, has been compared with enoxaparin?+?VKA in the EINSTEIN trials. The objective was to evaluate the cost-effectiveness of rivaroxaban compared with enoxaparin?+?VKA as anticoagulation treatment for acute, symptomatic, objectively-confirmed DVT or PE.

Methods:

A Markov model was built to evaluate the costs, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios associated with rivaroxaban compared to enoxaparin?+?VKA in adult patients treated for acute DVT or PE. All patients entered the model in the ‘on-treatment’ state upon commencement of oral rivaroxaban or enoxaparin?+?VKA for 3, 6, or 12 months. Transition probabilities were obtained from the EINSTEIN trials during treatment and published literature after treatment. A 3-month cycle length, US payer perspective ($2012), 5-year time horizon and a 3% annual discount rate were used.

Results:

Treatment with rivaroxaban cost $2,448 per-patient less and was associated with 0.0058 more QALYs compared with enoxaparin?+?VKA, making it a dominant economic strategy. Upon one-way sensitivity analysis, the model’s results were sensitive to the reduction in index VTE hospitalization length-of-stay associated with rivaroxaban compared with enoxaparin?+?VKA. At a willingness-to-pay threshold of $50,000/QALY, probabilistic sensitivity analysis showed rivaroxaban to be cost-effective compared with enoxaparin?+?VKA approximately 76% of the time.

Limitations:

The model did not account for the benefits associated with an oral and minimally invasive administration of rivaroxaban. ‘Real-world’ applicability is limited because data from the EINSTEIN trials were used in the model. Also, resource utilization and costs were based on the US healthcare system.

Conclusion:

Rivaroxaban is a cost-effective option for anticoagulation treatment of acute VTE patients.     

A Spatial Cross–Sectional Analysis of Elasticity of Demand for Soccer

Several studies estimate the demand for watching English professional football (soccer) as highly inelastic, a puzzling result given that clubs appear to possess a degree of monopoly power. We discuss weaknesses in earlier studies and offer an alternative method of assessing elasticity based on travel costs of spectators living different distances from the grounds. We find that elasticity varies across the 20 senior clubs for which data were available but in almost every case demand is more elastic than reported in the existing literature and pricing policy appears therefore to be more orientated towards profit maximisation than previously thought.