The Effects of Intermarriage on the Earnings of Female Immigrants in the United States

This paper investigates the effects of intermarriage on the earnings of female immigrants in the United States. The main empirical question asked is whether immigrant females married to US-born spouses have higher earnings than those of immigrant females married to other immigrants. Using 1970 and 1870 samples of IPUMS data, I estimate an earnings equation through OLS. I also correct for the labor force selection bias using the Heckman procedure. I finally take into account the endogeneity of intermarriage and apply a twostage least squares (2SLS) estimation procedure. I find that there is a positive marriage premium among immigrant females in the United States but a negative intermarriage premium for exogamously married females compared to endogamously married females. My results show that the longer the immigrant stays in the host country, the higher her wages, which is evidence for the assimilation effect over time. I find some evidence for a negative labor force selection bias among immigrant females. In other words, higher human capital women may select themselves out of the labor force, while lower human capital women are working for wages. Among those who are in the labor force, however, married females earn more than singles. I also conclude that being an immigrant from an English-speaking country does not have any impact on wages. Both premiums become statistically insignificant in difference from zero when 2SLS is used as an estimation procedure

Imaginal and ovicidal effect of some insecticides against Bruchus pisorum L. (Coleoptera: Chrisomelidae)

peer-reviewedTrials were conducted in 2011 and 2012 at the Institute of Forage Crops, Pleven, Bulgaria, in order to study the imaginal and possible ovicidal effect of some insecticides against Bruchus pisorum under field conditions. Treatments with insecticides were started after the appearance of the first pea weevils eggs on pods located on the bottom two nodes. It was found that treatment with acetamiprid; thiacloprid; thiacloprid+deltamethrin; 50 g cypermethrin+480 g chlorpyrifosethyl, 50 g cypermethrin+500 g chlorpyrifosethyl and zeta-cypermethrin resulted in the cessation of additional oviposition on the lower nodes by Bruchus pisorum, due to the toxic effect of the insecticides on the pea weevil. It was found that spraying with acetamiprid and zeta-cypermethrin was the most effective. These insecticides significantly reduced the proportion of infected pods in comparison with the proportion of pods with eggs before the treatment by 30.2 and 27.4% and by 15.8 and 24.0% in 2011 and 2012, respectively. The use of acetamiprid and zeta-cypermethrin was also associated with the lowest percentage of infected seeds (21.7 and 23.6%, respectively), with the lowest percentage of infected seed in infected pods (40.5 and 42.5%, respectively) and the highest weight of 1000 infected seeds (161.94 and 182.04 g, respectively). It was concluded that the management of pea weevils in the crop with acetamiprid and zetacypermethrin can lead to satisfactory results when spray timing is chosen when the first eggs are visible

Risk Diversification in the Agricultural Sector in Bulgaria

The Bulgarian and Romanian European Union membership coincides with the Common Agricultural Policy (CAP) Reform. Applied till the 80s of the 20th century, the system of European subsidies which aimed at developing a functioning agricultural sector led to constant surplus of basic agricultural goods with high budget prices. During the 90s production quotas (e.g. the milk quotas of 1983) were introduced an emphasis was put on ecologically clean agricultural production. The CAP reform of 2003 reorganized the European subsidies in accordance with demand and stimulated farmers to produce what the market needed. Direct subsidies changed from payments based on territory to payments for farms. In order to cut surplus, the EU introduced an intervention system; fix quotas for the production of milk and sanctions for breaking them; restrictions on the export subsidies and the amount of cultivated land/number of bred animals for which farmers can receive subsidies. Bulgarian and Romanian farmers receive direct payments which maintain their incomes stable but lower compared to these of their European counterparts. At the same time they have to meet the same requirements concerning environment preservation, food safety, and humane treatment of animals (a requirement for “cross compliance”). These factors together with the heavy dependence of the agricultural sector on climate make the issue of researching the possibilities for minimizing investment risks through product diversification extremely significant. The main aim of this article is to identify the risks in the agricultural sector and assess the priority usage of various forms of diversification as an instrument for controlling risks. In addition, the article outlines / studies the possibilities for adding value to the agricultural sector by diversification of products and activities. The article is written as follows: M. Nikolova – chapter 2; M Linkova – chapter 1; abstract, introduction and conclusion joint action.sustainable agriculture, entrepreneurial solutions, risk, diversification, nontraditional activities

Multiplicative Noise Removal Using L1 Fidelity on Frame Coefficients

We address the denoising of images contaminated with multiplicative noise, e.g. speckle noise. Classical ways to solve such problems are filtering, statistical (Bayesian) methods, variational methods, and methods that convert the multiplicative noise into additive noise (using a logarithmic function), shrinkage of the coefficients of the log-image data in a wavelet basis or in a frame, and transform back the result using an exponential function. We propose a method composed of several stages: we use the log-image data and apply a reasonable under-optimal hard-thresholding on its curvelet transform; then we apply a variational method where we minimize a specialized criterion composed of an $\ell^1$ data-fitting to the thresholded coefficients and a Total Variation regularization (TV) term in the image domain; the restored image is an exponential of the obtained minimizer, weighted in a way that the mean of the original image is preserved. Our restored images combine the advantages of shrinkage and variational methods and avoid their main drawbacks. For the minimization stage, we propose a properly adapted fast minimization scheme based on Douglas-Rachford splitting. The existence of a minimizer of our specialized criterion being proven, we demonstrate the convergence of the minimization scheme. The obtained numerical results outperform the main alternative methods

Approximation Algorithms for Route Planning with Nonlinear Objectives

We consider optimal route planning when the objective function is a general nonlinear and non-monotonic function. Such an objective models user behavior more accurately, for example, when a user is risk-averse, or the utility function needs to capture a penalty for early arrival. It is known that as nonlinearity arises, the problem becomes NP-hard and little is known about computing optimal solutions when in addition there is no monotonicity guarantee. We show that an approximately optimal non-simple path can be efficiently computed under some natural constraints. In particular, we provide a fully polynomial approximation scheme under hop constraints. Our approximation algorithm can extend to run in pseudo-polynomial time under a more general linear constraint that sometimes is useful. As a by-product, we show that our algorithm can be applied to the problem of finding a path that is most likely to be on time for a given deadline.Comment: 9 pages, 2 figures, main part of this paper is to be appear in AAAI'1