Wheat variety yield data: Do commercial and public performance tests provide the same information?

Wheat yields from reported performance test results are of economic importance to wheat producers, since their profits depend on selecting the optimal variety for their location. However, our data shows differences in absolute and relative wheat yields between commercial and public wheat breeding program's performance test data in Kansas. Newly available data are used to test if the difference in yields arose from potential selectivity bias, and to determine the contribution of private and public wheat breeding programs to varietal yield improvement during 2007–2012. Both Heckman selection models and multiple regression showed no statistical evidence of the potential presence of selectivity bias rather, managerial practices, agronomic conditions, field location, and inherent genetic traits of the seed variety were identify as the source of yield differences.     

Waiting for Signaling Quality

When a durable good of uncertain quality is introduced to the market, some consumers strategically delay their buying until the next period, with the hope of learning the unknown quality. I analyze the monopolist's pricing and waiting strategies when consumers have strategic delay incentives. I show when the monopolist offers introductory low prices in pooling equilibria. I also find two types of separating equilibria: one where the high‐type monopolist signals its quality by choosing a different price than the low‐type monopolist in the first period and another where the high‐type monopolist announces the product in the first period and waits to sell only in the second period. Waiting creates a credible cost for signaling; hence, the monopolist uses it as a signaling device.     

Analyzing the welfare‐improving potential of land in the former homelands of South Africa

This article contributes to the debate on the role of land in reducing poverty in rural South Africa. It uses the year of arrival in the former homelands as an instrument for land access and size. This identification strategy is based on the fact that African households were forcibly relocated to the homelands during the apartheid. Due to increasing population pressure, later arrivals were less likely to be assigned land. The results show that land has a large positive effect on household welfare. Because the homelands are relatively disadvantaged areas, these results provide a lower bound for the positive effects of land on household welfare.     

Rivaroxaban for non-valvular atrial fibrillation and venous thromboembolism in the Netherlands: a real-world data based cost-effectiveness analysis

Background: Non-vitamin K antagonist oral anticoagulants (NOACs) have been included in international guidelines as important alternatives to vitamin K antagonists (VKAs) for the treatment of venous thromboembolism (VTE) and stroke prevention in non-valvular atrial fibrillation (NVAF). Meanwhile, in the Netherlands, NOACs are widely used next to VKAs. The objective of this study is to estimate the cost-effectiveness of treatment with rivaroxaban compared to VKAs in NVAF and VTE patients in the Netherlands, using data from international prospective observational phase IV studies.

Methods: Two models were developed to represent NVAF and VTE patients, populated with patients from the XANTUS (NCT01606995) and XALIA (NCT01619007) international prospective observational studies. The 1-year cost-effectiveness of rivaroxaban use, compared to VKAs, was explored in a population consisting of NVAF and VTE patients (base case) as well as for four scenarios with sub-populations: NVAF patients only, VTE patients only, NVAF patients with unstable international normalized ratio (INR), and NVAF patients using an INR self-measuring device.

Results: In the base case, rivaroxaban saved €72,350 and gained 21 quality-adjusted life-years (QALYs) in a simulation of 2,000 patients over the use of VKAs. Ergo, rivaroxaban was dominant over VKAs. The probabilistic sensitivity analysis showed a probability of 85% for rivaroxaban being dominant and 100% at a willingness-to-pay threshold of €20,000/QALY. Rivaroxaban appeared to be dominant in all scenarios as well, except for the NVAF-patients-only scenario where the incremental cost-effectiveness ratio (ICER) was €157/QALY.

Conclusions: In patients with NVAF or VTE, rivaroxaban treatment is likely to be cost-effective and a potentially cost-saving alternative to VKA in the Netherlands.     

User Fee Abolition and the Demand for Public Health Care

This research examines the effect of the abolition of user fees in South Africa, a policy implemented in 1994 for uninsured children under the age of six and the elderly uninsured, as well as pregnant and nursing mothers. The analysis focuses on the implementation of the policy and the use of curative public healthcare services by children following strict and fuzzy regression discontinuity designs. The estimates point to statistically insignificant average and local average policy effects, even though the policy appears to have been implemented reasonably effectively, albeit imperfectly. In other words, the policy did not, on average, affect the use of curative public healthcare, at least for those children who should have benefited from the policy.     

Economies of Desire: Sexuality and the Sex Industry in the 21st Century

New data from sex surveys confirm that demand for commercial sex is based on permanent disparities between male and female desire, and is therefore ineradicable. Demand and supply are growing, facilitated by economic growth, the Internet, globalisation and changing sexual attitudes. A key objection to the sex industry is that pornography, lap dancing and prostitution promote rape and other kinds of violence against women. However, the evidence contradicts this contention. The commercial sex industry is impervious to prohibitions and cannot be eliminated. Laws which constrain sellers of sexual services or criminalise purchasers are not evidence‐based, and are bound to fail, wasting public resources.     

Can Agents Be Better Off with Pay Caps?

A popular way to discipline the managers of companies or banks that got into trouble during the recent financial crisis has been to impose caps on managers' pay. Using a small extension of the standard principal–agent model, we argue that pay caps might serve the opposite purpose, because the agent might be better off with a pay cap. Specifically, we show that, given a fixed effort level to be implemented, the agent's expected utility can be decreasing in an upper bound for the agent's reward. The effect of pay caps on the general structure of optimal incentive contracts is also characterized. While an improvement of contracting information always helps the principal, it might increase or decrease the marginal cost of imposing pay caps.     

An econometric analysis of demand for food quantity and quality in urban China

This article offers an analytical framework for studying consumer demand for food quality based on a theory‐consistent demand model, namely, the Exact Affine Stone Index specification. Importantly, it accounts for unobserved consumer and regional heterogeneity, and allows for arbitrary Engel curves. The empirical value of our framework is illustrated in an econometric analysis of demand for food quality in China. Evaluating possible structural changes in consumer food expenditures in China is of paramount importance, given the ever‐increasing global role of China and the implications of the structural food preference changes for the global food system. The major findings emerging from this study indicate that income is an important determinant of demand for food quality and quantity with the relatively more affluent provinces having a higher affinity for food quality.     

Graduated Punishments in Public Good Games

I explain the ubiquitous use of graduated punishments by studying a repeated public good game in which a social planner imperfectly monitors agents to detect shirkers. Agents’ cost of contributing is private information and administering punishments is costly. Using graduated punishments can be optimal for two reasons. It increases the price of future wrongdoing (temporal spillover effect) and it can lead to bad types revealing themselves (screening effect). The temporal spillover effect is always present if graduated punishments prevail, but screening need not occur if agents face a finite horizon. Whether or not a screening effect is exploited has a substantial impact on both outcomes and actual punishments. If the temporal spillover effect is sufficiently strong, then first‐time shirkers are merely warned.     

Predicting Interest Rate Volatility Using Information on the Yield Curve

This study examines whether information on the yield curve is useful for predicting volatility of the yield curve. The information is used within dynamic models by specifying the covariance matrix of changes in yield factors as nonlinear functions of the factors. Using such models, it is found that the information (i) is useful for predicting volatility of the slope factor, achieving the accuracy comparable with the GARCH model; (ii) has incremental value for predicting volatility of the curvature factor when combined with a volatility‐specific factor; and (iii) does not much improve prediction of volatility of the level factor once the volatility‐specific factor is introduced.