Bryan Caplan set off a debate which has spread to many corners of the blogosphere. I have no interest in recapping and evaluating the whole thing but I'd like to make a simple but neglected point: negative liberty and positive liberty are not separable.
Here is one simple scenario. Let's say the government tells me I have to buy and place a five-foot ceramic grizzly bear statue on my front lawn. How bad an act of coercion is that? If I have an upper-middle class income, it's an inconvenience and an aesthetic blight but no great tragedy. If I have a Haitian per capita income, it is a very bad act of coercion and it will impinge on my life prospects severely. I either give up some food or they send me to jail.
In other words, even theories of negative liberty — purely libertarian theories where only negative liberty seems to matter — require standards for degrees of coercion. Those standards will very often depend on how much wealth the victims of the coercion have and they will depend on a more general concept of positive liberty. Negative liberty standards can't help but seep into a concern with consequences.
Fast forward to said debate. When people are poor, apparently small interventions can be quite crushing and quite coercive. To cite the "smaller" interventions of 1880 doesn't much convince me. The real impact of the depredations against women was very, very large, even from some "small interventions" (and I don't think they were all small).
(Also, I would not in this case take the *legal* oppressions to be a stand-alone or exogenous variable, separable from more general societal attitudes. There were various male desires to oppress women, which took a mix of legal and non-legal forms. Asking how bad the "government-only" restrictions were is an odd division of the problem, since the governmental and non-governmental restrictions were an integrated package which worked together in non-linear fashion.)
Every negative liberty theorist is a positive liberty theorist in disguise and this comes out once they start citing degress of outrage, degrees of harm, degrees of coercion, and the like.