We read with great interest the recent work in PNAS by Shover et al. revisiting the relationship between medical cannabis laws and opioid overdose mortality. They expand the 2014 Bachhuber et al. by adding 7 recent years of mortality data to cover a longer study period 1999-2017. They suggest...

Even though surface water has been polluted almost everywhere in China, few economic valuation studies have been conducted to value water quality changes. This paper reports an economic valuation study conducted in Yunnan, China, which estimates the total value of a real investment project to...

While polluted surface water is encountered across most of China, few economic valuation studies have been conducted on water quality changes. Limited information about the economic values associated with those potential water quality improvements or deteriorations is a disadvantage for making...

One of the major difficulties in doing cost-benefit analysis of a development project is to estimate the total economic value of project benefits, which are usually multi-dimensional and include goods and services that are not traded in the market. Challenges also arise in aggregating the values...

Water quality in China has seriously deteriorated in recent years. However, very few valuation studies have been conducted to estimate the monetary values associated with water quality changes. As a result, the decision makers can hardly make rational choices with regard to investments in water...

While polluted surface water is encountered across most of China, few economic valuation studies have been conducted on water quality changes. Limited information about the economic values associated with those potential water quality improvements or deteriorations is a disadvantage for making...

One of the major difficulties in doing cost-benefit analysis of a development project is to estimate the total economic value of project benefits, which are usually multi-dimensional and include goods and services that are not traded in the market. Challenges also arise in aggregating the values...