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I see the struggle (edits you've made) with understanding the issue but it comes down to legal process of creating land owners - concept of enclosure, where previously it was not used as such (private ownership of land). Put it another way, motivation for pecuniary benefits. All the other factors matter, of course, but if the (previous) tenants were not motivated, they would not work the lands.
This article explains it.
Upvote:3
The question as it is framed is difficult to answer because every time and place was a bit different. All the changes in agriculture mentioned may have been relevant to different degrees in different cases. But at least in the earliest stages, a key factor that warrants emphasis (in addition to those mentioned in the question) is the impact of rapid population growth.
During most of the 14th and 15th centuries England's population steadily dropped, due largely to plague. As population recovered in the 16th century, more intensive forms of agriculture became possible, enabling conversions of waste into pasture and pasture into arable. So as England's population roughly doubled in about a century, it's fairly obvious that the economics of agriculture were changed by this. Later on in the eighteenth and nineteenth centuries, waves of population growth and enclosures at least roughly coincided, but at that point the interplay between demographics and techno-economic changes (the Agricultural and Industrial Revolutions) were more complex.
Even in later periods, local waves of enclosure were driven at least in part by population growth and migration. For example, here is how Ian Whyte (2005, p. 49) describes certain forms of enclosure in northern counties of England:
Many commons had their margins nibbled away by encroachments made either by local people or incomers, a process which was tolerated where the amount of waste was large, creating patterns of small, irregular closes still clearly visible around the margins of former commons like Cartmel in the southern Lake District. Also widespread from the fifteenth to the nineteenth centuries was the practice of small groups of farmers enclosing areas of common with a ring fence and creating private stinted pastures which only they had the right to use.
Such informal enclosures weren't necessarily driven by greater profitability so much as by competition for growing numbers of people for limited land.