$$
\newcommand{\uns}[1]{\mathbf{1}[#1]}
\newcommand{\esp}[1]{\mathbf{E}[#1]}
\newcommand{\hatesp}[1]{\hat{\mathbf{E}}[ #1 ]}
\newcommand{\espE}{\mathbf{E}}
\newcommand{\Ind}{\perp\kern-5pt\perp}
\newcommand{\var}[1]{\mathbf{V}[ #1 ]}
\newcommand{\hatvar}[1]{\hat{\mathbf{V}}[ #1 ]}
\newcommand{\cov}[1]{\mathbf{C}[ #1 ]}
\newcommand{\plim}[1]{\text{plim}_{ #1 \rightarrow \infty}}
\newcommand{\plims}{\text{plim}}
\newcommand{\distr}{\stackrel{d}{\rightarrow}}
\newcommand{\partder}[2]{\frac{\partial #1}{\partial #2}}
\newcommand{\partdersq}[2]{\frac{\partial^2 #1}{\partial #2^2}}
\DeclareMathOperator{\diag}{diag}
\DeclareMathOperator{\asym}{Asym}
$$