Before revision:  The main motivation for introducing the \alpha,[a,b] -convex decreasing stochastic orders is that they allow us to derive novel comparative statics results for important applications in economics that could not be derived using previous stochastic orders.
After revision:  The main motivation for introducing the \alpha,[a,b] -concave stochastic orders allow us to derive novel comparative statics results for important applications in economics that could not be derived using previous stochastic orders.