No, socialization of the economy is not the only metric. It is not even the key metric. The class character of the state is primary. Socialization is a single, highly important factor within that determination, but it remains derivative. A nationalized industry under bourgeois state command functions as state monopoly capital.

Evaluation proceeds from the principal contradiction to its secondary aspects. The principal question: which class holds monopoly over political power and the means of coercion? This determines the direction of all other processes. Secondary metrics, the rate and depth of socialization, the trajectory of productive forces, the composition of administrative personnel, the character of ideological struggle, these are not irrelevant. They are conditional. They either consolidate proletarian state power or undermine it. There is no neutral technical criterion. The same policy, e.g. grain procurement or industrial planning, produces opposite class effects depending on which class commands the state apparatus.

The state is not a passive vessel for economic measures. It is the organized expression of class rule. Transitionary societies contain multiple modes of production in contradiction. The state resolves which mode dominates. Empirical assessment must therefore begin with the class basis of political power.