Mekong River Basin: Perception vs. Reality? Perception is Reality?

So much of my work is based on perception of reality. I believe that perception drives decision-making for big and small things. You decide which lettuce to buy in the shop based on what you can see, but also maybe what the label reads (if you shop in a place that labels), maybe you want to buy from a particular farm, maybe a particular region, maybe you like a specific color or turgidity, maybe you have had the lettuce before and prefer it to others you've tried. But you are not tasting lettuce in the store, only observing and making a decision. This is based on your perception and preference.

This human behavior is as true for buying lettuce as it is for making high level state decisions. I am not suggesting that people make decisions that are flippant. I am suggesting that people make decisions with information at their disposal, and information, some call facts, can be largely based on perceptions rather than on reality. At what point does perception become reality?

I am working in the Mekong River basin. I am staying in Laos. There is a perception that is being generated by the international community and activists through the press and whatever other channels of communication, that the Xayaburi Project is problematic. One of the reasons stated is how it will hold back sediment. In my initial data gathering I found something pretty astounding, if it is in fact true. The amount of sediment that this Project potentially holds back is minimal and insignificant compared with the amount of sediment being removed throughout the basin: through sand and gravel mining,  numerous tributary dams, upstream dams in China, and levee and small structures on tributaries.

So, the current fear and assertion that sediment trapping by this Project is a reason to criticize it seems to me to be more based on perception and fear, rather than on reality.