Infrastructure development remains best way to rein escalating land prices. But considering its not likely soon , best alternatives must be considered.
Idle land tax concept introduction will be politicised and hard to implement equally and efficiently to all. Let us not think if the law has been possible elsewhere like US it will be successful in Kenya.
I tend to believe we should sturdy and learn from some Asian countries- high population with many poor. Yet low land related violence.
1. You must develop your land 3yrs after acquiring. Failure you pay specific penalties. - that will reduce speculation.
2.inheritance tax should be introduced. Equivalent to a third or half of land value.- this will reduce uneconomic subdivision which to me is far worse than speculation.
That law should apply only to new land acquired e.g from July2015 to ensure unpleasant tensions and disruption are minimized.

We can reduce that by being specific on implementation. That is all new land transaction which involves change of ownership starting from example 2015 July.
Imagine those energetic , lazy young people drinking and loitering around in our rural Kenya waiting for their parents to subdivide those small portions. Some even murdering their own parents to quicken inheritance process. I suggest slap them with 50% inheritance tax on the land value. Meaning it will be economical to sell whole portion intact or put it in productive use. Then the buyer must put it in proper use within 3yrs or punitive penalties. That will usher in a new era of WORKING NATION.

Sounds great but it also will mean a change of culture. Currently sale of ancestral land is frowned upon in many cultures.

from this live ngilu grilling on ktn here

http://www.standardmedia.co.ke/ktn/live

there are so many legal lacunas in the land law. The national land commsision needs to be reconstituted with experts.