… to pay to protect a river in Thailand can help put a tangible price-tag on the river’s benefits — from clean water to flood control — and … are easily overexploited and degraded. Of course, putting a price-tag on a river’s services is hard — but not impossible. One option is to … in Chiang Mai , asking how much they would be willing to pay to conserve the Ping and reduce the effects of environmental degradation — …