Equanimity in the Aghatavinaya Sutta In the Aghatavinaya Sutta, there are five antidotes given for arisen ill-will(āghāto). I am puzzled because one of these is to develop equanimity ("upekkhā tasmiṃ puggale bhāvetabbā") and another is to reflect on ownership of kamma, which is used to generate (/is the cause of) equanimity as I understand it. I don't understand what is intended by having these separate. Full text follows.


  "There are these five ways of subduing hatred by which, when hatred
  arises in a monk, he should wipe it out completely. Which five?
  
  "When one gives birth to hatred for an individual, one should develop
  good will for that individual. Thus the hatred for that individual
  should be subdued.
  
  "When one gives birth to hatred for an individual, one should develop
  compassion for that individual. Thus the hatred for that individual
  should be subdued.
  
  "When one gives birth to hatred for an individual, one should develop
  equanimity toward that individual. Thus the hatred for that individual
  should be subdued.
  
  "When one gives birth to hatred for an individual, one should pay him
  no mind &amp; pay him no attention. Thus the hatred for that individual
  should be subdued.
  
  "When one gives birth to hatred for an individual, one should direct
  one's thoughts to the fact of his being the product of his actions:
  'This venerable one is the doer of his actions, heir to his actions,
  born of his actions, related by his actions, and has his actions as
  his arbitrator. Whatever action he does, for good or for evil, to that
  will he fall heir.' Thus the hatred for that individual should be
  subdued.
  
  "These are five ways of subduing hatred by which, when hatred arises
  in a monk, he should wipe it out completely."
Looking at the text, it does not recommend reflecting on the ownership etc of kamma as a method of developing equanimity (upekkha). Here it is specifically for removing resentment (āghāta). As far as I can tell from searching the electronic Pāli Canon the idea of reflecting on kamma is never linked with upekkhā.
In reflecting on kamma one is taking the approach to hindrances (nīvaraṇa), which Kamalashila in his book Meditation: The Buddhist Way of Tranquility and Insight calls, &quot;considering the consequences&quot; (pg 54-5). The other four are: cultivate the opposite (mettā &amp; karuṇā); cultivate a &quot;sky-like mind&quot; (upekkhā); suppression (don't think of the person or asatiamanasikāro); and lastly going for refuge (not included here). This list and Kamalashila's are not a perfect match, but seem to be similar in intent. They are methods for dealing with the hindrances in preparation for practising jhāna.
I'm not sure whether it is helpful to think in terms of a hierarchy of &quot;effectiveness&quot;. One has a number of techniques one can use to help deal with the hindrances, and tries each of them until one works.
The reflection on kamma comes from a list of five things to continuously reflect on famously found at AN 5.57, titled Abhiṇhapaccavekkhitabbaṭhāna Sutta (The Discourse of Facts to be Continuously reflected On) in the Burmese Ed. of the Canon. In this text it gives the benefit (athavasa) of doing this practice of reflecting on the consequences:

atthi, bhikkhave, sattānaṃ kāyaduccaritaṃ vacīduccaritaṃ manoduccaritaṃ. tassa taṃ ṭhānaṃ abhiṇhaṃ paccavekkhato sabbaso vā duccaritaṃ pahīyati tanu vā pana hoti. idaṃ kho, bhikkhave, atthavasaṃ paṭicca ‘kammassakomhi, kammadāyādo kammayoni kammabandhu kammapaṭisaraṇo, yaṃ kammaṃ karissāmi — kalyāṇaṃ vā pāpakaṃ vā — tassa dāyādo bhavissāmī’ti abhiṇhaṃ paccavekkhitabbaṃ itthiyā vā purisena vā gahaṭṭhena vā pabbajitena vā.
There is, Monks, bad conduct (duccarita) of body, speech and mind by beings. But when one continuously reflects on [this reflection on kamma], then such wickedness is completely abandoned or it is [at least] diminished.

Thus the point of this practice is not so much generating upekkha as it is the elimination of wicked conduct (duccarita). And resentment (āghāta) is clearly a form of mental wicked conduct, a mano-duccarita, in the language of the Abhiṇhapaccavekkhitabbaṭhāna Sutta. Reflecting on the consequences of such wickedness will help the person who aims to eliminate the hindrance in preparation for meditation. Clearly this has more general ethical applications as well, but it seems the main context is meditation and eliminating the hindrances.