Okounkov–Pandharipande parity conjecture for the Hilbert scheme of points on affine three-space

Fix $n\in\mathbb{Z}_{\geq 0}$, let $\mathrm{H}_n=\operatorname{Hilb}^n(\mathbb{A}^3)$ be the Hilbert scheme of ideals of colength $n$ in $\mathbb{C}[x,y,z]$, and let $T_I\mathrm{H}_n$ denote the tangent space at a point $I\in\mathrm{H}_n$. Parity conjecture. One has

$$(-1)^n=(-1)^{\dim_{\mathbb{C}}T_I\mathrm{H}_n}$$

for all $I\in\mathrm{H}_n$. This conjecture extends the parity identity known for monomial ideals and is attributed in the source to Okounkov and Pandharipande. Its status is not resolved in the supplied text.