This paper considers identifying and estimating the Average Treatment Effect on Treated (ATT) when untreated potential outcomes are generated by an interactive fixed effects model. That is, in addition to time-period individual effects, we consider case where there is unobserved time invariant variable whose effect may change over which can therefore cause (in absence of participating treatment...

In this paper, we study the matrix period and competition of Toeplitz matrices over a binary Boolean ring B={0,1}. Given subsets S T {1,…,n−1}, an n×n A=Tn〈S;T〉 is defined to have 1 as (i,j)-entry if only j−i∈S or i−j∈T. We show that max⁡S+min⁡T≤n min⁡S+max⁡T≤n, then A has d/d′ where d=gcd⁡(s+t|s∈S,t∈T) d′=gcd⁡(d,min⁡S). Moreover, it shown limit sequence {Am(AT)m}m=1∞ directed sum all ones exce...

degradation of natural habitats and decreasing of genetic diversity of populus caspica led to vast reduction of its regeneration and growth potential in north of iran. hence, the growth potential of mass-produced seedlings was compared with their parents. for this purpose, the ramets of three selected seedlings from 17 parent trees belonging to north of iran, along with ramets of their parent t...