Project description:Bis(5-methyl-2-[(2-nitrophenyl)amino]-3-thiophenecarbonitrilyl)acetylene, a derivative of the highly polymorphic compound 5-methyl-2-[(2-nitrophenyl)amino]-3-thiophenecarbonitrile (ROY) that possesses two chromophores electronically coupled through a triple bond, was found to be trimorphic. Structural data for two of these forms indicates that symmetry is maintained in one structure and broken in the other leading to spontaneous differentiation of the methyl-thiophenecarbonitrile units. This study contributes to the mounting evidence that ROY and its derivatives are particularly prone to polymorphism.
Project description:The literature on treatment effects focuses on gross benefits from program participation. We extend this literature by developing conditions under which it is possible to identify parameters measuring the cost and net surplus from program participation. Using the generalized Roy model, we nonparametrically identify the cost, benefit, and net surplus of selection into treatment without requiring the analyst to have direct information on the cost. We apply our methodology to estimate the gross benefit and net surplus of attending college.