Thanks for your comments.

1. This is a fair point. In the Supplemental Material, we explore cross-country differences in email usage. When we statistically adjust for country-level differences in email usage (using World Bank data), the country ranking remains essentially the same (adjusted rankings correlate over 0.90 with non-adjusted rankings). Also, when you restrict the data only to drop-offs performed at hotels -- which tend to rely on email more than other settings -- you see the same pattern of results.

2. Also a good point. However, there are mechanical problems with using the marginal differences between conditions -- for example, countries with high reporting rates in the NoMoney condition will be naturally capped in the possible size of the treatment treatment effect, compared to those with low reporting rates. Because the scale is bounded at 0 and 100% you're also fighting against reversion to the mean at the low and high ends of the distribution. FWIW we find that absolute levels of reporting rates correlate very highly with other known proxies of honesty both within and between countries (measures like tax evasion, corruption, etc), whereas relative differences between conditions do not.

3. We explicitly test this by randomly varying whether the wallets contained a key or not (valuable to the owner but not the recipient), while holding the rest of the contents in the wallet constant.

The world bank tells you half of the Chinese firms have emails but you won't know that far less than that of them ARE WILLING to use it. For taxing, they use super informal wechat group to send around notifications. I doubted if my tax officer remembers his email or has it at all. Regression adjustment or group it as outlier you know the best.

For hotels, I had experience that a 5-star hotel responded my message after almost a month. They have it but not in your way of using it.

Anyway, did you know the reason for their not writing that email?

Super agree. The designer of the experiment really need to read some books. And has him considered the situation that the “wallet” might be returned to the policed station?

May I ask you have investigate those things:1:Does workers in receptions have a email? Is it better to leave multiple communication ways?(as far as I know, net communication is a separate department in China) 2:I realized that you are considering the language problem, why don’t you use local language?(I believe most of your wallets receptors Understand English, but it’s not meaning they could write a English letter). 3:could u explain why didn’t receive email lead to dishonesty? To Chinese culture, just like japan, leave the lost things in a certain place is a common thing. The real dishonest is: you come back to the desk and can not the wallet back. Chinese is very passive in many ways( I confirmedly admit that), but call it dishonesty is ridiculous，especially you include none of Chinese culture-relative country in the paper.

First point is really important. I can give email addresses to 100 people in India and ask them to message an important medical information (something of high value to recipient and no value to this person, at negligible effort) and the conversion would be quite low. Email for unacquainted users is perceived to be hard. Large part of India and other developing countries became digital without going through the internet of 90s and early 2000s. So email is foreign to large mass of people.

Great point about email. Speaking from experience, lots of people in India simply don't know how to send email.

For example my MIL is a medical doctor, so is obviously educated, speaks English well and uses a smart phone but wouldn't be able to send email to a new contact. Same with WhatsApp, she can reply to messages from us but I don't think she knows how to add a new contact to her phone.

They could always ask their kid or someone they know with a smartphone?

That sounds like something my mother would ask me if (and previously when) she didn’t know how to email someone. Although it’d definitely lower the “conversion” rate regardless given the varying smartphone/PC ownership combined with internet penetration rates.

Yes, they can try many ways to get it done. However, the effort and time that they would pay is indeed diminishing the will to contact the owner. It's not a fair comparison. Even if you give it an email index from world bank, that still doesn't tell how normal citizens' acquaintance in using email.

What if there's no kid though? My MIL lives alone, and this is the kind of thing you can't explain over the phone.

Speaking from experience as we once tried to help her to connect to a open WiFi which needed an OTP-based login via the phone and gave up after about 15 frustrating minutes for all three of us!

It's never easy explaining anything computer related over a phone.

I've noticed working in design that people generally underestimate the average human's ability to solve problems, even if they aren't technically literate. But any increase in the effort department would reduce the amount of returns no doubt.