Most Difference-in-Difference (DD) papers rely on many years of data and focus on serially correlated outcomes. Yet almost all these papers ignore the bias in the estimated standard errors that serial correlation introduces. This is especially troubling because the independent variable of...

Income-maximizing consumers should vote in predictable ways: support for liberal, redistributive governments should fall as income rises. But weak empirical evidence for these voting patterns might suggest that voters are influenced by alternative factors, such as perceptions of social mobility...

In this book, I introduce basics of research methodologies in Arabic language which I believe is an unprecedented step. The conceptions, research frameworks, sampling and some detailed methods are given in this text book. Moreover, some analytical statistical methods are introduced to give...

This note addresses the properties of mean-reverting stochastic processes of the Black-Karasinski type with additional stochastic jumps. For these processes, which are well suited for many financial applications such as the modelling of commodity prices and credit spreads, one would usually like...

This paper consists of two parts, a theoretical followed by an empirical contribution. We first give a new framework for fractional differencing in discrete time and show how the definition of fractional differencing that is commonly employed in empirical financial applications arises as a...

Popular smoothing techniques generally have a difficult time accommodating qualitative constraints like monotonicity, convexity or boundary conditions on the fitted function. In this paper, we attempt to bring the problem of constrained spline smoothing to the foreground and describe the details...

Momentum is widely accepted among academic researchers as one of the strongest return generating factors, yet it remains largely unknown by the investing public. This paper explores that dichotomy by examining momentum from a practical point of view. Using exchange traded fund data from 2002...