Aggregate effects of social security reform in 2008

In this study, we investigate the effects of social security reform in 2008 on aggregate variables. We focus only on to the change in retirement age of this reform by leaving the other structural and administrative changes aside. Our main results are as follows: (i) social security reform has a great positive effect on capital accumulation; (ii) aggregate labor supply in efficiency units increases while mean labor hours remain relatively costant; (ii) social security tax rate to balance the budget of social security system decreases dramatically

Aggregate efficiency in random assignment problems

We introduce aggregate efficiency (AE) for random assignments (RA) by requiring higher expected numbers of agents be assigned to their more preferred choices. It is shown that the realizations of any aggregate efficient random assignment (AERA) must be an AE permutation matrix. While AE implies ordinally efficiency, the reverse does not hold. And there is no mechanism treating equals equally while satisfying weak strategyproofness and AE. But, a new mechanism, the reservation-1 (R1), is identified and shown to provide an improvement on grounds of AE over the probabilistic serial mechanism of Bogomolnaia and Moulin (2001). We prove that R1 is weakly strategyproof, ordinally efficient, and weak envy--free. Moreover, the characterization of R1 displays that it is the probabilistic serial mechanism updated by a principle decreed by the Turkish parliament concerning the random assignment of new doctors: Modifying the axioms of Hasimoto, et. al. (2012) characterizing the probabilistic serial mechanism to satisfy this principle, fully characterizes R1

Assortative Mating and Inequality

This paper studies the evolution of assortative mating based on the permanent income (the individual-specific component of income) in the U.S., its role in the increase in family income inequality, and the factors behind this evolution. I first document a remarkable trend in the assortative mating, as measured by the permanent-income correlation of couples, across families formed around 1970 and those formed around 1990. I show that this trend accounts for almost one-third of the increase in family income inequality across these family cohorts. I then argue that the increased marriage age across these cohorts contributed to the assortative mating and thus to the rising inequality. Individuals face a large degree of uncertainty about their permanent incomes early in their careers. If they marry early, as most individuals around 1970 did, this uncertainty leads to weak marital sorting along permanent income levels. But when marriage is delayed, as around 1990, the sorting becomes stronger as individuals are more able to predict their likely future incomes. After providing reduced-form evidence on the impact of marriage age, I build and estimate a marriage model with income uncertainty, and show that the increase in marriage age can explain almost 75 percent of the increase in the assortative mating

Sızma Testleri İçin Bir Model Ağ Üzerinde Siber Saldırı Senaryolarının Değerlendirilmesi

The scope of this work is to investigate the effects of baffle cut and baffle spacing on the heat transfer coefficient and pressure drop in a shell and tube heat exchanger. For this aim, analyses are made for a standard dimensioned heat exchanger with variable baffle cut and spacing. It is observed that both heat transfer coefficient and pressure drops values decrease with the increase of baffle cut and baffle spacing. This paper demonstrates successful application of Genetic Algorithm for the optimal design of shell-and-tube heat exchangers. Approximate design methods for shell-and-tube have been investigated and a generalized procedure has been developed to run the GA algorithm and to find the global minimum heat exchanger are