Should most effort be put into what is 'most important'?

Everything could be better but we only have limited capabilities to fix and improve things. It is therefore important to ask how should we prioritize our efforts.

One idea you often hear is that we should put our efforts into what are the 'most important' things. What is considered important varies, for instance, finding a cure to a terrible disease is important because many people die from this disease. Fixing some societal problem is important because the problem causes much inequality among people. Developing friendly A.I. is important because evil A.I. could take over the world. Improving our educational system is important because it could have a huge impact on the productiveness of our society.

What is common for all of these, is that the possible benefits from solving the problem are very large. Although prioritization based on possible benefits can sometimes work as the rule of thumb it includes a pitfall: Even if we put a lot of effort into solving the very important problem, it might be that the problem won't be solved or the state of the world improves only very little.

Taking importance into account is a good start but including a second factor will greatly improve our prioritization ability.
This is ease of changing. The idea is simple: The easier something is to change, the bigger influence our efforts will have. In the abovementioned examples, one could ask, for example: How easy it is to find a cure to this disease? How much influence do we have over fixing this societal problem? How much can we advance the search for friendly A.I. with todays actions?

This consideration leads to the following 'prioritization equation':

So what, you may ask. Isn't all of this obvious?

My response is: it should be! I blog about this topic because so often I see 'ease of changing' neglected when discussing prioritisation.

Last week, for instance, I came across an exercise task related to using linear regression models. The exercise went along these lines:
Alphawolves' scores on average is given by formula: 

0.18 x Passing skill + 0.25 x Shooting skill + 0.12 x Player compatibility.

Which skill should Alphawolves' focus in practise to best improve their scoring?

A trick question I thought - the answer must be 'cannot be determined'.

This option, however, was not available. What I thought was that shooting skill may be the most important thing for scoring but what if it cannot be taught at practise? Might be that training passing skills is twice easier.

This example is relevant because the course is instructed by a renowned scholar from a good U.S. University (see: Model Thinking, Coursera). Even he can suffer from the bias of neglecting ease of changing.

Another examples comes from my personal experience. 

Few years ago we did a school project for the SEB bank related to increasing the credit card usage of their clients. We ended up doing a segmentation analysis which revealead (not so surprisingly) that older women, who spoke Russian as the first language, who lived around Tallinn were a big client group that used much cash. 

Later, we gave a presentation about the results to SEB executives and suggested that more effort should be put into changing the cash-usage habits of those older Russian ladies living in Tallinn.

After the presentation we got some feedback and one executive commented:"the teenage, Russian speaking women living in Tallin use surprisingly much cash. This is a segment we really could influence". 

This guy clearly did not suffer from the 'neglecting ease of changing'-bias.

Recently I came to think that maybe people neglect 'ease of changing' because it is more difficult to estimate than 'importance'. For example, it is easy to see that developing cure to cancer is important and basically nobody will disagree with you. However, it is much harder to say how likely we are to succeed in developing the cure if we put 10 million dollars into the research.

Despite of this, the prioritization equation still includes the two components which are 'importance' and 'ease of changing'. Ease of changing shoud not be neglected on the grounds that it is difficult to estimate. All we can do is try out best.