From weed to wealth? Prospects for medic pastures in the Mediterranean farming system of north-west Syria

Medic (Medicago spp.) pastures are widely grown in rotation with dryland cereal crops in Mediterranean climate zones of Australia. Attempts since the 1960's to introduce this system to Mediterranean west Asia and north Africa (the native region of medic) have not lead to significant adoption; farmers in the region recognize medic, but as a weed and natural pasture plant. This first detailed economic evaluation of the rotational medic system was conducted using a whole-farm linear programming model based on the agricultural system of north-west Syria. The model represents in detail impacts of rotation on yields, labor requirements of alternative farm activities, availability of family and hired labor, subsistence income requirements, livestock feed sources and uses at different times and a choice of sheep stocking rates. Biological data for the analysis are based on a large six-year cropping and grazing experiment near Aleppo on terra-rossa soil with rainfall mainly in winter and averaging about 330 mm annually. The trial compared a dryland medic-wheat system and traditional two-year rotations of wheat with: fallow, watermelon, lentil and vetch. Results indicate that, given current prices and yields from the trial, medic is less profitable than traditional rotations. The model was used to investigate situations in which medic would be economically preferred. Selection of a medic rotation by the model was found to be particularly sensitive to the area of the farm and the price of labor. On small farms, labor availability per hectare is high, favouring the production of labor intensive crops such as lentil and watermelon. On larger farms, labor costs of these enterprises are substantial, increasing the relative profitability of medic, especially if labor prices increase. Interestingly, the relative desirability of medic is more sensitive to its impact on subsequent wheat crops than to the level of pasture production. We also found that modest increases in the prices of sheep products (especially milk) have a major impact on the economic performance of medic. These insights will allow improved focusing and targeting of future research and extension activities.     

Regime switching in the yield curve

The article investigates the effect of interest‐rate variance on the shape of the yield curve with the use of a bivariate two‐state Markov switching model for the short‐rate changes and the yield curve slope. The two states are characterized by the variance of the short‐rate changes: low and high variance. In the high‐variance regime the yield curve becomes steeper with the interest‐rate variance; in the low‐variance regime the slope is independent hereof. A nonswitching specification amounts to averaging across the two states. The economy is in the high‐variance state during unusual economic periods. © 2004 Wiley Periodicals, Inc. Jrl Fut Mark 24:315–336, 2004     

Measurement of the Socioeconomic Impact of Lake Restoration: An Assessment Model Employing a Benefit/Cost Cross-Impact Probabilistic Approach

A bstract . A number of lake restoration demonstraton projects have been launched by the Environmental Protection Agency as a result of Public Law 92-500. To evaluate the cost-effectiveness of these public investment projects requires the development of an assessment model. The proposed Benefit/Cost Cross-Impact Probabilistic Approach (BCCIPA) is one attempt at assessing the interdependent socioeconomic and environmental impacts of the lake restoration project over time, both quantitatively and qualitatively, so that various changes brought about by the project can be investigated and evaluated in two comparative stages for three points in time—before, during and after project implementation.     

The risk-return trade-off in human capital investment

In this paper, we analyze investments in human capital in a way which is standard for financial assets, but not (yet) for human capital assets. We study mean-variance plots of human capital assets. We compare the properties of human capital returns using a performance measure and by using tests for mean-variance spanning. Fields differ strongly not only in common rates of return, but also in return per unit of risk. We identify a range of educations that are efficient in terms of investment goods, and a range of educations that may be chosen for consumption purposes.     

Implicit social preferences in the Norwegian system of indirect taxation

The revelation of implicit social preferences is a fresh field of econometrics. In this paper the theoretical setting is a model of optimal indirect taxation. A parametric preference function is specified, which makes it possible to separate and quantify three different effects. First, it provides a condensed quantitative measure of the degree of income inequality aversion. Second, a set of parameters evaluate external social costs induced by the consumption of certain commodities. Finally, the function allows estimation of implicit equivalent income scales. The authors consider the results as a source of information about an important part of Norwegian tax policy.     

Implied Volatility of Interest Rate Options: An Empirical Investigation of the Market Model

We analyze the empirical properties of the volatilityimplied in options on the 13-week US Treasury bill rate. These options havenot been studied previously. It is shown that a European style put optionon the interest rate is equivalent to a call option on a zero-coupon bond.We apply the LIBOR market model and conduct a battery of validity tests tocompare three different volatility specifications: contact, affine, and exponentialvolatility. It appears that the additional parameter in the affine and theexponential volatility function is not justified. Overall, the LIBOR marketmodel fares well in describing these options.     

An Anatomy of Price Dynamics in Illiquid Markets: Analysis and Evidence from Local Housing Markets

This research analyzes the dynamic properties of the difference equation that arises when markets exhibit serial correlation and mean reversion. We identify the correlation and reversion parameters for which prices will overshoot equilibrium ("cycles") and/or diverge permanently from equilibrium. We then estimate the serial correlation and mean reversion coefficients from a large panel data set of 62 metro areas from 1979 to 1995 conditional on a set of economic variables that proxy for information costs, supply costs and expectations. Serial correlation is higher in metro areas with higher real incomes, population growth and real construction costs. Mean reversion is greater in large metro areas and faster growing cities with lower construction costs. The average fitted values for mean reversion and serial correlation lie in the convergent oscillatory region, but specific observations fall in both the damped and oscillatory regions and in both the convergent and divergent regions. Thus, the dynamic properties of housing markets are specific to the given time and location being considered.     

Telemedizin – Angebote,Chancen und Kosteneffektivität

Digitalisation of the health care system proceeds. Therefore it is to be expected that telemedicine applications will also be introduced into health care. Currently, the number of telemedicine applications in Germany is low and it is also scarce in comparison to foreign countries. This is striking because it is usually supposed that telemedicine applications have got a great potential to improve health care and reduce expenditures. Hence, this publication discusses offers, chances and the cost-effectiveness of telemedicine.     

Are impatient farmers more risk-averse? Evidence from a lab-in-the-field experiment in rural Uganda

Based on data from a field-experiment in rural Uganda, we show that impatient farmers are more risk-averse than patient farmers. We relied on a simplified version of the Convex Time Budget (CTB) method to elicit farmers’ time preferences and on an independent method for eliciting their risk-preferences. We report two important findings. First, we show that our simplified CTB method applied to farmers from Uganda replicates the key findings of Andreoni and Sprenger’s lab experiments that involved student subjects. Second, we establish the existence of a negative correlation between risk tolerance and impatience, based on two independent measures.