Equity market neutral hedge funds and the stock market: an application of score-driven copula models

In this article, we study the time-varying market neutrality of equity market neutral hedge funds. We use data from the Hedge Fund Research? Equity Market Neutral Index (HFRX EH), which represents the performance of a portfolio of individual equity market neutral hedge funds. For each day, we measure different levels of association of the Standard and Poor’s 500 (S&;P 500) index and the HFRX EH. We use non-linear dynamic conditional score models of location, scale and copula that, to the best of our knowledge, have not yet been applied in the body of literature on hedge funds. We study whether the neutrality of the HFRX EH that is evidenced in the body of literature for the period of April 1993–April 2003 also holds for the following decade, for the period of May 2003–December 2016. We estimate different average levels of association for the pre-, during- and post-periods of the US financial crisis of 2008. We find that the association of the S&;P 500 and the HFRX EH, on average, is significantly positive for the pre- and post-periods of the financial crisis, and it is significantly negative for the period during the financial crisis.     

Stochastic labelling of biological images

Many hypotheses made by experimental researchers can be formulated as a stochastic labelling of a given image. Some stochastic labelling methods for random closed sets are proposed in this paper. Molchanov (I. Molchanov, 1984, Theor. Probability and Math. Statist. 29 , 113–119) provided the probabilistic background for this problem. However, there is a lack of specific labelling models. Ayala and Simó (G. Ayala and A. Simó, 1995, Advances in Applied Probability 27 , 293–305) proposed a method in which, given the whole set of connected components, every component is classified in a certain phase or category in a completely random way. Alternative methods are necessary in case the random labelling hypothesis is not reliable. A different kind of labelling method is proposed that considers the environment: the type of every connected component is a function of its location.
Two different biphase images are studied: a cross section of a nerve from a rat, and a cross section of an optic nerve from a lizard.     

Regime-switching purchasing power parity in Latin America: Monte Carlo unit root tests with dynamic conditional score

We suggest a Monte Carlo simulation-based unit root test of the purchasing power parity theory for Latin American countries. Under the null hypothesis, we use a Markov regime-switching (MS) model with unit root in the conditional location and MS volatility dynamics. Under the alternative hypothesis, the proposed test incorporates Markov regime-switching autoregressive moving average (MS-ARMA) plus MS volatility dynamics. Under both the null and alternative hypotheses, one of the volatility models estimated is Beta-t-EGARCH, which is a recent dynamic conditional score volatility model. We use data on real effective exchange rate time series for 14 Latin American countries. For each country, we estimate by Monte Carlo simulation the critical values of the unit root test. We provide an economic discussion of the unit root test results and also study the robustness of MS-ARMA plus MS volatility with respect to smooth transition autoregressive models with Fourier function.     

How do services of owner-occupied housing affect income inequality and redistribution?

This paper aims at analyzing the redistributive impact that the inclusion of the imputed rental market value of owner-occupied housing would have if used for quantifying the ability to pay rather than imputation based on cadastral values. We consider the Spanish personal income tax as reference, due to the differential treatment that it provides for imputed income from owner-occupied housing, together with the exceptionally high percentages of home ownership in Spain. By means of micro-simulation we explore the consequences of alternative possibilities for dealing with implicit income from owner-occupied housing.     

Are medium‐scale farms driving agricultural transformation in sub‐Saharan Africa?

This study presents evidence of profound farm‐level transformation in parts of sub‐Saharan Africa, identifies major sources of dynamism in the sector, and proposes an updated typology of farms that reflects the evolving nature of African agriculture. Repeat waves of national survey data are used to examine changes in crop production and marketed output by farm size. Between the first and most recent surveys (generally covering 6 to 10 years), the share of national marketed crop output value accounted for by medium‐scale farms rose in Zambia from 23% to 42%, in Tanzania from 17% to 36%, and in Nigeria from 7% to 18%. The share of land under medium‐scale farms is not rising in densely populated countries such as Kenya, Uganda, and Rwanda, where land scarcity is impeding the pace of medium‐scale farm acquisitions. Medium‐scale farmers are a diverse group, reflecting distinct entry pathways into agriculture, encouraged by the rapid development of land rental, purchase, and long‐term lease markets. The rise of medium‐scale farms is affecting the region in diverse ways that are difficult to generalize. Findings indicate that these farms can be a dynamic driver of agricultural transformation but this does not reduce the importance of maintaining a clear commitment to supporting smallholder farms. Strengthening land tenure security of local rural people to maintain land rights and support productivity investments by smallholder households remains crucial.     

The Effect of Providing Monetary Information on Energy Savings for Household Appliances: A Field Trial in Spain

Journal of Consumer Policy - Energy labels are one of the most widely used policies in the European Union for increasing the energy efficiency of household appliances. However, their effectiveness...     

A Case of Mistaken Identity? Measuring Rates of Improved Seed Adoption in Tanzania Using DNA Fingerprinting

Studies of improved seed adoption in developing countries are almost always based on household surveys and are premised on the assumption that farmers can accurately self-report their use of improved seed varieties. However, recent studies suggest that farmers’ reports of seed varieties planted, or even whether the seed is local or improved, are sometimes inconsistent with the DNA fingerprinting results of those crops. We use household survey data from Tanzania to test the alignment between farmer-reported and DNA-identified maize seed types planted. In the sample, 70% of maize seed observations are correctly reported as local or improved, while 16% are type I errors (falsely reported as improved) and 14% are type II errors (falsely reported as local). Type I errors are more likely to have been sourced from other farmers, rather than formal channels. An analysis of input use, including seed, fertiliser, and labour allocations, reveals that farmers tend to treat improved maize differently, depending on whether they correctly perceive it as improved. This suggests that errors in farmers’ seed type awareness may translate into suboptimal management practices. The average yield of seed that is correctly identified as improved is almost 700 kg per hectare greater than that of type I errors. This indicates that investments in farmers’ access to information, seed labelling, and seed system oversight are needed to complement investments in seed variety development.     

Releasing Control: Parents on Vacation

The paper examines the family vacation phenomenon by comparing parents on vacation (n = 203) with parents during daily life (n = 246) in terms of two psychological constructs: regulatory focus and parenting style. Results revealed that parents in both samples were similar in their ‘regulatory focus of promotion’ (need for challenges) and ‘parenting styles’ (permissive and authoritarian), but parents on vacation scored lower on both need for security (‘regulatory focus of prevention’) and authoritative ‘parenting style’. The findings suggest that parents, especially mothers, view family vacation as an opportunity to relax and release parental control. The findings' theoretical and practical implications are discussed. Copyright © 2012 John Wiley & Sons, Ltd.     

Housing deprivation and health status: evidence from Spain

Living in inadequate housing conditions not only supposes a failure of a basic functioning. It also has effects on other essential aspects of well-being such as health. This study questions to what extent living in poor housing conditions can determine individuals’ health status once the possible influence of other factors is controlled for. By estimating a logistic model with individual effects and a housing deprivation index based on a latent variable model, we reach a number of relevant conclusions concerning the relationship between these two different dimensions of multidimensional well-being. We find a negative effect of housing deprivation on the individuals’ health, both when housing conditions are introduced in a disaggregated manner in the model and when they are combined in a latent variable.