There are two worlds of more or less equivalent technological level, say a difference of only a few decades and no more than 50 years. A first contact event occurs and after the hoopla dies down trading starts.
Initially, barter is the primary form of trade but this quickly becomes cumbersome.
How would the two economies first establish a currency exchange and exchange rate?
Some commodities are similar and occur in similar quantities, particularly minerals gold, iron etc. Other commodities are unique to one civilization or the other; plants and animals unique to each planet, unique tech developed by one and not the other.
- Both planets have one currency or at least a dominant currency (like the USD)
- Neither planet is in a "dominant" economic or technological position.
- Travel between the planets takes a few days
- There is a moderate level of trust in business dealings but it is not clear how laws apply to off worlders on each planet.
Ideas I've toyed with:
- comparable commodity-based exchange, ie. gold standard type exchanges, but this seems archaic for technologically advanced worlds and would anyone really want to transport heavy gold out of the gravity well of a planet
- some type of crypto type exchange, but this seems problematic with distance and not very conducive to trade as the price fluctuates