  We are interested in the existence of Pareto solutions to the vector
optimization problem $$\text{Min}_{\,\mathbb{R}^m_+} \{f(x) \,|\, x\in
\mathbb{R}^n\},$$ where $f\colon\mathbb{R}^n\to \mathbb{R}^m$ is a polynomial
map. By using the {\em tangency variety} of $f$ we first construct a
semi-algebraic set of dimension at most $m - 1$ containing the set of Pareto
values of the problem. Then we establish connections between the Palais--Smale
conditions, $M$-tameness, and properness for the map $f$. Based on these
results, we provide some sufficient conditions for the existence of Pareto
solutions of the problem. We also introduce a generic class of polynomial
vector optimization problems having at least one Pareto solution.
