-1
$\begingroup$

In classical econometric models, we typically study linear relationships of the form:
$$ Y = C_1 X_1 + C_2 X_2 + \dots + C_n X_n + \epsilon, $$
where $Y$ is a scalar dependent variable, $X_1, X_2, \dots, X_n$ are scalar independent variables, $C_1, C_2, \dots, C_n$ are scalar coefficients, and $\epsilon$ is the $1$ dimensional error term.

However, in my case:

  • $Y$ is a $k$-dimensional vector ($Y \in \mathbb{R}^k$),
  • $X_1, X_2, \dots, X_n$ are also $k$-dimensional vectors, and
  • $C_1, C_2, \dots, C_n$ are $k \times k$ matrices.

The model takes the form:
$$ Y = C_1 X_1 + C_2 X_2 + \dots + C_n X_n + \epsilon, $$ and $\epsilon$ is the $k$ dimensional error term.
where the addition and multiplication are matrix-vector operations.

My question is: Has such a model been formally described in the literature? If so:

  1. Who introduced this model, and in what context?
  2. Are there any specific references or foundational papers/books that discuss this type of model?

Is this a suitable topic for a master’s dissertation? If so, what areas or questions within this framework could be worth exploring?

I would appreciate any pointers to theoretical discussions or applications of this type of vector-valued linear econometric model.

$\endgroup$
4
  • 1
    $\begingroup$ I haven't seen that before myself but it's pretty similar to multivariate regression. See this for the similarities. brilliant.org/wiki/multivariate-regression Note that you can't have a scalar $\epsilon$ if you have a vector response. $\endgroup$
    – mark leeds
    Commented Nov 26 at 15:36
  • $\begingroup$ @markleeds In multivariate regression on left hand side we have $Y$ which is a $n \times 1$ vector. In this model $Y$ is form as $n$ vectors each one $k$ dimensional. Thanks - you are right about $\epsilon$ $\endgroup$
    – Darek
    Commented Nov 26 at 16:01
  • $\begingroup$ Darek, you are referring to now is multiple regression, @markleeds is referring to an equation of the form $Y = XB + \varepsilon$ where $Y$ and $\varepsilon$ are $n \times p$ matrices, $X$ is $n \times q$ matrix and $B$ is $q \times p$ (I use $n$ to denote sample size, if you take $n = 1$ and the transpose you would get the model in your post for a single observation). You may find more if you search for Seemingly Unrelated Regressions (SUR), or e.g. here (bashtage.github.io/linearmodels/system/…). $\endgroup$
    – minginator
    Commented Nov 26 at 16:47
  • $\begingroup$ Darek: I was just pointing out that it looks similar to multivariate regression. minginator seems to have a good grip on this material ( I don't ) so it's best to let him help you. And thanks to minginator for expressing my comment more clearly. $\endgroup$
    – mark leeds
    Commented Nov 27 at 22:07

0

You must log in to answer this question.