An obvious indicator is to normalise by population. The true Olympic country will provide sporting opportunity for more of its citizens, rather than a super-funded elite few. The following graph shows top 30 countries (left to right) to live as determined by lifestyle.org. This blog does not make any comment on the methods used to provide this list and assumes that it is more or less valid.
It can be seen that first, by normalising to population, the achievements of the USA and UK are significantly diminished. As Iceland and Luxembourg are particularly small countries and, in Iceland, the weather may play a part in the restriction of outdoor activities, there is a general trend in medal success from left to right. Two of the indicators that would appear to be linked to athletic success would be health (New Zealand scores highest in this category) and work life balance, the social democratic Scandinavian countries and the Netherlands scoring highest here.
So while some countries may supercharge their medal count by pouring funds behind the selected few, when normalising by population it appears it is not surprisingly those countries that prioritise the many that come top of the table.