Impossible trinity is like the Hindu mythology trinity…

Deepak Mohanty compare the two trinities in a speech on capital flows and controls at ADB conference:

 Capital flow management has been perceived to be challenging particularly in the context of Mundell’s ‘impossible trinity’ of fixed exchange rate, independent monetary policy and open capital account. All the three cannot be pursued simultaneously, and at least one should be sacrificed. Which one has to be sacrificed? Well, it depends upon country-specific situation and available policy options. This reminds me of an old adage in Hindu mythology, which is somewhat similar to impossible trinity: that the idols of Brahma (the creator), Vishnu (the preserver), and Shiva (the destroyer) cannot be kept under the same roof! Among three, who should be kept out? There is no rule or convention. It is left to the choice of individual households and their belief and faith.

Superb..Let me add some bit to this…

In case of hindu trinity the choice became clearer as thanks to a curse given to Brahma. Brahma  was first cursed  that he would not  be worshipped which was later eased to worshiping only at Pushkar. So initially, you typically had  Shiva and Vishnu in most of the temples. However, overtime as the story got lost people started having more Brahma in the temples…

In impossible trinity the choice was never really clear…Based on experiences, fixed exchange rate became like Brahma here with most developed and some developing countries letting their exchange rate move as per markets..So Capital mobility and independent monetary policy became the Shiva and Vishnu (not in any order)..

However, some Asian economies which were not happy with leaving exchange rates fully to the markets…Hence they are trying to manage the impossible trinity just as you have temples with all the trinities these days..