i feel like an #oddeven party pooper (reducing and working are not the same)

there are two nice, evidence-informed op-ed pieces out today on delhi’s odd-even scheme to try to reduce air pollution (here and here). the results are heartening because i didn’t have a good sense of whether a two week window of implementing a policy — to which there were many exceptions — was long enough to potentially detect a statistically significant change in meaningful measures of pollution. nor, admittedly, did i feel that i was breathing cleaner air the past two weeks. as one the articles points out, much of the anecdotal chatter has been about clearer roads, not about clearer skies.

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since i live in delhi, am certainly affected by the air quality, and worried about my health accordingly (plume tells me every day that the situation is dire), i was pretty pleased to wake up to the headline “yes delhi, it worked.” and what has indeed happened is that good evidence (rigorously obtained, as laid out by suvojit) has been generated of a statistically significant reduction in nasty particulate matter (pm 2.5) (by 18%) during the hours the intervention was in effect.

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this was a policy that i wanted to see work, so i am pleased that the evidence shows a reduction in the particulate matter that is driving many of my good friends out of the city (alongside many other woes). but we must be careful — whether something “worked” is more subjective than is the evidence of a reduction, which greenstone and colleagues have nicely and rapidly documented.

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if models had predicted a 50% reduction, we wouldn’t have been so thrilled about 18%. if the government had said that every little bit counts and that even a 5% reduction would be counted by them as a success and a reason to commit to continuing the program, then indeed, 18% is quite impressive.

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moving forward, as delhi tries to clean up its act and hopefully become a model for the rest of the country, clarifying up-front decision-points and definitions of success will be important. for the next pilots — because delhi desperately needs such measures — how will we declare, in a rigorous and defensible way, that a policy effort ‘worked’ well enough to be scaled and continued?  those of us interested in promoting the use of rigorous evidence and evaluation to inform decision-making need to be slightly cautious in our interpretations and celebrations of victory when we haven’t said up front what we’ll count as a triumph.

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*as an addendum (31 jan 2016), it is not clear that the researchers themselves penned the title ‘yes delhi, it worked.’ for the benefit of the doubt, i am hoping that the researchers submitted something more along the lines of ‘yes delhi, odd-even reduced pollution’ and that the newspaper itself opted to change it. but the point holds that success is subjective and therefore requires a definition, preferentially ex ante.

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delhi’s #oddeven plan had a significant effect on pollution

agree that this is a potentially good sign about individual citizens being willing to engage in collective action – note also that many were most excited about lessened traffic, which is a good reason to think about inspiring collective action in ways that bring about both a public good and a private gain, allowing the pursuit of direct and indirect policy goals. my sense is there is still a long way to go in convincing people that the pollution is a problem and getting worse.

Suvojit Chattopadhyay

Researchers Michael Greenstone, Santosh Harish and Anant Sudarshan have some news for us. Hard data that shows that the Odd-Even plan reduced pollution by significant levels in Delhi. The headline: this study finds there was an 18% reduction in PM 2.5 due to the pilot during the hours that the rule was in effect. The effect size is truly staggering, and is quite unusual for studies that use such rigorous methodology to look at the impact of policy interventions.

Starting January 1, while absolute pollution levels increased both inside and outside Delhi (for atmospheric reasons, as noted by other commentators), the increase in fine particle levels in Delhi was significantly less than in the surrounding region. Overall, there was a 10-13 per cent relative decline in Delhi.

Around 8 am, the gap between Delhi’s pollution and that in neighbouring regions begins to form and steadily increases until mid afternoon. As temperatures…

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revisiting maximum city amid delhi’s air pollution

earlier this week, a friend responded to this article on delhi’s pollution levels by reporting to facebook:

in the last week, 2 of my friends have moved back (one permanently & the other temporarily) to the states because of peak pollution levels. others are booking flights to leave the city for portions of the winter

it seems that most of the adaptations we strive towards are restricted to creating healthy spaces for ourselves amongst the pollution that most of the city’s residents cannot escape. 

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what she is saying, and is right, is that those of us that can and are staying in delhi are partially creating an air-istocracy. some of us are able to refine the very most public of goods — the air — for ourselves. a public good is by definition non-rivalrous and non-excludable. and yet we are working to make breathable air exclusive: in our flats, in our enclosed vehicles, in our office spaces, behind our masks.

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this needs to change, lest we become confined to these bubbles and delhi becomes even less friendly to pedestrians and cyclists and generally to taking a stroll or letting in a bit of fresh air through the windows.

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what i wrote on facebook, and i stand by at risk of being offensive, is this: in a considered and intentional, if provocative, turn of phrase to indicate violation or abuse without consent, delhi rapes my lungs on a daily basis.

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this intended to play on one of the major threats the outside world sees about living in delhi. the point is not to belittle violence against women experienced in delhi — which i have been merciful in not experiencing but which is a reality — or other forms of structural violence coped with on a daily basis. worrying about and living with these forms of violence wear people down to the point that they feel they can’t deal with something like the air. and so it goes undiscussed. but clean air is not ignorable. it is a form of violence and it needs to be addressed.

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to tackle a problem of the common or public good is a challenge anywhere; it is deeply bound up with ideas of citizenship and the social contract, of paying taxes and the role of government and the space for activism. it requires a government that can impose regulations to protect public goods and it requires citizens to expect and demand this of their government, though it is not a commodity that can be handed out. it is about far more than putting up ‘clean city, green city’ signs (as, incidentally, tackling violence against women is about more than hanging up coasters in taxis and autos declaring (in english) that the vehicle respects women).

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delhi and india, perhaps in particular, have a lot of work to do. i hope the world stays tuned and that india rises to the challenge. to close, i’ll allow someone else —  mehtu in maximum city — to muse on public goods in india (a passage that, ironically, i first read in the much cleaner air of rishikesh):

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the flats in my building are spotlessly clean inside; they are swept and mopped every day, or twice every day. the public spaces – hallways, stairs, lobby, the building compound – are stained with betel spit; the ground is littered with congealed wet garbage, plastic bags, and dirt of human and animal origin. it is the same all over bombay, in rich and poor areas alike. this absence of a civic sense is something that everyone from the british to the hindu nationalists have drawn attention to, the national defect in the indian character (p. 138).

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