Saturday, April 30, 2016

Income and longevity, almost all you need to know


The Association Between Income and Life Expectancy in the United States, 2001-2014 

The estimates of impact of income on longevity are now available for US. And the results are clear. The summary of the article in 4 statements:
First, higher income was associated with greater longevity throughout the income distribution.The gap in life expectancy between the richest 1% and poorest 1% of individuals was 14.6years (95% CI, 14.4to 14.8years) for men and 10.1 years (95% CI,9.9 to 10.3 years) for women.
Second, inequality in life expectancy increased over time. Between 2001 and 2014, life expectancy increased by 2.34 years for men and 2.91 years for women in the top 5%of the income distribution, but by only 0.32 years for men and 0.04 years for women in the bottom 5%(P < .001 for the differences for both sexes).
Third, life expectancy for low-income individuals varied substantially across local areas. In the bottom income quartile, life expectancy differed by approximately 4.5 years between areas with the highest and lowest longevity.Changes in life expectancy between 2001 and 2014 ranged from gains of more than 4 years to losses of more than 2 years across areas.
Fourth, geographic differences in life expectancy for individuals in the lowest income quartile were significantly correlated with health behaviors such as smoking(r = −0.69,P < .001),but were not significantly correlated with access to medical care, physical environmental factors, income inequality, or labor market conditions. Life expectancy for low-income individuals was positively correlated with the local area fraction of immigrants (r = 0.72, P < .001), fraction of college graduates (r = 0.42, P < .001), and government expenditures (r = 0.57, P < .001). 
Differences are huge. Confronting the issue from a policy perspective is not that easy. Individual health behaviors are the key to understand what's going on.

PS. Inequality on income or wealth?. This could be the next article...

Josep Segú
Encants Nous, oli sobre tela, 80 × 220 cm


Friday, April 29, 2016

European health regulation on lab tests, the final round? (2)



Last week, Theranos clinical lab has received more bad news. Though the final resolution is still pending, all available informations raise concerns about the acuracy of such lab.Could this happen in Europe? My feeling is that the outdated and obsolete regulation could replicate the story.
In Europe, in vitro diagnostics regulation was decided 18 years ago!. The last proposal debated two years ago in the Parliament got no final agreement. I have explained the inefficiency of european parliament formerly. Health care safety and quality deserves better regulation and specially in lab tests.
Beyond safety issues, the value of lab tests require deeper assessment. Current proposals are not taking into account properly this issue. Now is the moment to introduce it in the final proposal, otherwise it will forgotten for the next two decades.

PS. Have a look at this article: A Systematic Review of Health Economic Evaluations of Diagnostic Biomarkers

Manhattan i Queens (Fragment), oli sobre tela, 60 × 150cm


Platforms, a business model

Platform scale

Platform Scale (n): Business scale powered by the ability to leverage and orchestrate a global connected ecosystem of producers and consumers toward efficient value creation and exchange.

The new hype on business models is around platforms. Well, this is not new, a decade ago David Evans wrote Catalyst Code but its impact was limited. Now "Platform scale" and "Platform revolution" are the two required business books. If you want to understand the economic foundations go to "Platform Economics".
The topic requires more elaboration than a post in a blog. How this trend affects health care in practice remains to be seen.
The Platform Manifesto
1. The ecosystem is the new warehouse
2. The ecosystem is also the new supply chain
3. The network effect is the new driver for scale
4. Data is the new dollar
5. Community management is the new human resources management
6. Liquidity management is the new inventory control
7. Curation and reputation are the new quality control
8. User journeys are the new sales funnels
9. Distribution is the new destination
10. Behavior design is the new loyalty program
11. Data science is the new business process optimization
12. Social feedback is the new sales commission
13. Algorithms are the new decision makers
14. Real-time customization is the new market research
15. Plug-and-play is the new business development
16. The invisible hand is the new iron fist

Sunday, April 17, 2016

Economic Ethics

Oxford Handbook of Professional Economic Ethics

Some economists, while watching the film Inside job, were astonished by Martin Feldstein statements and justifications of banks with toxic assets. I was one of them. Too many conflicts of interest sorrounded his words. When I saw him, I thought, this is the "health economist" that wrote: Economic Analysis for Health Service Efficiency: Econometric Studies of the British National Health Service. n 1967 (!). This was one of my first readings in health economics many-many years ago.
While I was reading the following paragraph in a new book, I thought that the topic deserved a deeper approach to economists' ethics:
The question of whether there is a profound tension between our professional norms and our self interest deserves careful attention. Conflict of interest in economics gained much  (unwanted) attention after the documentary Inside Job accused some finance economists of doing analysis favorable to financial industry interests while receiving undisclosed  pay from those same interests. Even if you believe, as I do, that Inside Job was unfair to some of its targets, it did fuel a crisis of confidence in economists that we all have a  strong interest in correcting. The response has been to strengthen the norms that we  disclose possible conflict of interests in our research and policy recommendations; this is surely a good thing. An example from my own field of development is that researchers on foreign aid should disclose whether they are employees of or consultants to agencies  dispensing foreign aid (or conversely, recipients of funding from antiaid interests).
Yet the issue of conflict of interest is too complex to be so quickly dismissed by a simple  disclosure requirement.
The handbook by DeMartino and McCloskey is an excellent contribution to shed some light on the issue:
The case for economic ethics is simple and, we think, undeniable. Economists enjoy tremendous influence today over the life chances of others—innumerable others. That is the heart of the matter. The influence of economists arises from their expertise in a field vital to social wellbeing,
freedom, and other valued goals. As economists know better than anyone, when you monopolize a resource that others need, you exert power over them. Moreover, in recent years, economists’ influence has been amplified by institutional developments. Independent central banks, the  multilateral development banks, and other international financial institutions are often in a position to set economic policy and even engage in social engineering without much oversight by elected  officials or the public. Economists are at the helm of such institutions and occupy staff positions in the departments where the actual work gets done. Combined with its intellectual monopoly,  institutional power enhances the ability of the economics profession to alter the course of human affairs—for the better, of course, but also, sometimes, for the worse.
 ...
Influence over the lives of others, which can be immense, coupled with the risk of doing even substantial foreseeable and unforeseeable harm, implies that economic practice is ethically fraught. And yet the profession largely manages to ignore the attending burdens. Perhaps because economists understand that harm is universal in economics, the Hippocratic tradition appears to offer no insight into how economists should comport themselves. What does “do no harm” mean in a world where there are no free lunches and where all actions (including doing nothing) entail tradeoffs? And perhaps because economists often paint on big canvases, where they affect the lives of thousands or even millions of people all at once rather than individual clients one by one, clinical ethics seems largely irrelevant. The scale of economic interventions generates among economists a fear that serious and open engagement with professional ethical issues  would paralyze them with doubt in those moments of human need when what is called for instead is focused audacity.
 This is a real call for action into an improvement of practices and behaviors of economists.





Art Basel Hong Kong

Friday, April 15, 2016

Where is the trade-off?

The fallacy of the equity-efficiency trade off: rethinking the efficient health system

What goes first? An equitable health system or an efficient one?. You'll see in some textbooks this biased trade-off formulation.
 A more appropriate question would be, “what is more important for a population, a health system that delivers equitable (fairly distributed) health outcomes or a health  system that maximises health gains?” The difference between the meaningless first question (which does not contrast outcomes) and the potentially meaningful second question (which does contrast outcomes) is critical.
 On a continuum of health gains and equity, possible goals of a health system include:
✯ Achieving the greatest health gains for a given input without regard to whether this means concentrating the gains in one (social) group: a traditional health outcomes focus,
✯ Achieving the fairest distribution of health for a given input without regard to the actual level of health achieved: a non-traditional outcome focus on (one form of) health equity, and
✯ Achieving an appropriate balance between the greatest health gains for a given input subject to the constraint of fairly distributing the health gains across social groups: an outcome balancing health equity and health gains
If finally there is a prioritisation on waiting lists, we would focus on the third option. Unfortunately I wrote a post 5 years ago on the same topic...and still waiting for its application.

PS. The trade off started with A. Okun 40 years ago, from a macroeconomics perspective. Have a look at the anniversary at Brookings.

PS. "Public health refers to all organized measures (whether public or private) to prevent disease, promote health, and prolong life among the population as a whole. Its activities aim to provide conditions in which people can be healthy and focus on entire populations, not on individual patients or diseases. Thus, public health is concerned with the total system and not only the eradication of a particular disease." WHO dixit. Can you imagine asking citizens about a Public Health Survey?. The term doesn't make any sense. All over the world the common term is Health Survey if you want to ask people about their health perception, except in Catalonia. So weird, somebody should check it, maybe it's a mistake.





Thursday, April 14, 2016

The badness and the wrongness of inequality

 On inequality

Two ideas from the philosopher Harry Frankfurt: (1) from a moral point of view, economic equality does not really matter very much, and (2) there is a misunderstanding of the relationship between treating people equally and treating them with respect.

Both ideas are covered in an new book. Some selected statements:
Economic equality is not, as such, of any particular moral importance; and by the same token, economic inequality is not in itself morally objectionable. From the point of view of morality, it is not important that everyone should have the same. What is morally important is that each should have enough. If everyone had enough money, it would be of no special or deliberate concern whether some people had more money than others. I shall call this alternative to egalitarianism the “doctrine of sufficiency”—that is, the doctrine that what is morally important with regard to money is that  everyone should have enough.
Some philosophers believe that an equal distribution of certain valuable resources, just by virtue of being egalitarian, is a significant moral good. Others maintain that what actually is of moral importance is not that the resources be distributed equally but that everyone enjoy the same level of welfare. All of these philosophers agree that there is some type of equality that is morally valuable in itself, quite apart from whatever utility it may possess in supporting efforts to achieve other morally desirable goals.
It is easy to confuse being treated with the sort of respect in question with being treated equally. However, the two are not the same. I believe that the widespread tendency to exaggerate the moral importance of egalitarianism is due, at least in part, to a misunderstanding of the relationship between treating people equally and treating them with respect. The most fundamental difference between equality and respect has to do with focus and intent. With regard to any interesting parameter—whether it pertains to resources, welfare, opportunity, rights,  consideration, concern, or whatever—equality is merely a matterof each person’s having the same as others. Respect is more personal. Treating a person with respect means, in the sense that is germane here, dealing with him exclusively on the basis of those aspects of his particular character or circumstances that are actually relevant to the issue at hand.
Demands for equality have a very different meaning in our lives than do demands for respect. Someone who insists that he be treated equally is calculating his demands on the basis of what other people have rather than on the basis of what will accord with the realities of his own condition and will most suitably provide for his own interests and needs. In his desire for equality, there is no affirmation by a person of himself. On the contrary, a concern for simply being equal to others leads people to define their goals in terms that are set by considerations other than the specific requirements of their own distinctive nature and of their own circumstances. It tends to distract them from recognizing their most authentic ambitions, which are those that derive from the character of their own lives, and not those that are imposed on them by the conditions in which others happen to live.
I found the reference while reading The New Rambler. You'll find there the critical view. Strongly recommended for those interested in this topic and specially those that reject demagogy on using this term.



Tuesday, April 12, 2016

The key piece of gear

La peça clau de l'engranatge

This is the original version of my abridged op-ed in El Punt Avui published last Sunday. (in catalan, you may use Google translator)




Tots aquells que han intentat definir les característiques determinants d’un sistema de salut eficient acaben observant que la coordinació assistencial esdevé una peça cabdal. Això vol dir que la presa de decisions clíniques és més acurada quan diferents professionals i organitzacions treballen en la mateixa direcció, la de millorar la salut i qualitat de vida de les persones. Dit així sembla força elemental, però la realitat és més complexa. Davant d’un procés d’atenció calen moltes aportacions diferents, des de molts àmbits diferents, amb un nivell de qualitat determinat. L’engranatge ha de funcionar sense grinyolar ni una mica.

Hayek fa 70 anys explicava en un article clàssic -“The use of knowledge in society”- com el mecanisme de preus és un instrument extraordinari per coordinar les decisions econòmiques, i com una peça d’informació tant limitada era capaç d’orientar les accions dels que produeixen i dels que consumeixen. En realitat, sabem que és va quedar curt i per tant sense desmerèixer el potencial del mecanisme hi ha prou evidència de les seves mancances si el prenem de forma aïllada.

El sector salut és un exemple de com la formació dels preus és controvertida per la pròpia naturalesa  de l’activitat.  L’oferta i la demanda de serveis assistencial no es coordinen majoritàriament pel mecanisme de preus, són els prescriptors que determinen quins altres professionals i organitzacions han de prendre part en la cadena de valor. És el criteri professional el que guia les decisions en el marc d’unes organitzacions sanitàries que tenen les seves regles de funcionament. I aquesta peça clau de l’engranatge és la fonamental: la de l’organització sanitària integrada que és capaç de definir rutes assistencials davant problemes de salut. Es tracta de definir qui fa què, quan i com. I això esdevé encara més rellevant en el cas de les malalties cròniques, motiu pel qual el Pla de Salut a Catalunya hi ha situat tot l’èmfasi de forma molt encertada.

Substituïm doncs els preus pel professionalisme en la coordinació i assignació de recursos, però no n’hi ha prou. Tota organització té un disseny d’incentius, d’allò que motiva l’acció per part dels seus membres, el professionalisme n’és una part però n’hi ha d’altres. La cultura organitzativa i els valors que la sustenten són determinants del comportament dels diferents actors. El valor que s’atorga al mèrit professional, a l’esforç, i a la qualitat esdevé singular de cada organització. Quan una organització és incapaç de enaltir l’excel·lència i reconèixer-la, aleshores hi ha dues possibilitats: aquells que s’han esforçat no es consideren reconeguts i se’n van – encara que algunes vegades ho fan parcialment-, o tots plegats acaben al que se’n diu regressió a la mitjana. En ambdós casos, hi ha una pèrdua potencial per a tothom. Cal dir que no em refereixo a una qüestió estricta del que se’n diu incentius tipus “pal o pastanaga”, de resposta a un estímul concret. Cal triar entre el context de “mediocràcia” o meritocràcia que és el que defineix l’actitud, el contracte implícit.

Per tal d’assolir la integració assistencial de forma exitosa cal garantir uns incentius acurats. L’enfoc professionalista és necessari però no suficient. I aquests incentius inacurats és precisament la història del que s’ha esdevingut a Catalunya des del 2003, quan va començar la prova pilot de compra poblacional en el sistema sanitari públic.  En aquell moment, determinades zones geogràfiques van assajar d’impulsar organitzacions sanitàries integrades a canvi d’una compensació de l’activitat de forma capitativa. Es trencava doncs des d’aquell moment el criteri de volum, quan més fas més gran és la compensació. S’entrava en una nova dinàmica on el conjunt de serveis de salut poblacionals de proximitat es compensaven pel nombre d’habitants. La innovació era extraordinària i de nivell, anava en la direcció correcta. En alguns casos va mostrar uns resultats excepcionalment bons. Però com sempre, una bona idea aplicada a mitges o sense calibratge fi en el temps, es dilueix. Lluny de reconèixer les mancances en l’aplicació, fins i tot sortien aquells que assenyalaven el desencert del pagament capitatiu.

Ens cal un exercici d’humilitat i aprendre de les realitats recents. El sistema sanitari català té un elevat potencial per desenvolupar l’atenció integrada però té males peces al teler. La primera de totes és el disseny institucional. L’obsessió per la controvèrsia “públic-privat” ens ha fet perdre el guió de la pregunta clau, quins són els valors i quins resultats volem. Si el principi que pretenem preservar és que no hi hagi distribució dels beneficis quan el finançament és públic, aleshores el problema està acotat i no cal donar-hi més voltes. Afecta molt marginalment al conjunt. La segona peça és la següent: si l’objectiu que pretenem és assolir el millor nivell de salut amb els recursos disponibles, aleshores ens hem de preguntar quins són els resultats relatius de les diferents organitzacions i professionals, i  admetre que cal compensar  diferencialment l’esforç per l’excel·lència i la qualitat. Si a tots els professionals i organitzacions se’ls assigna un criteri homogeni de compensació sense ajustar pel valor, aleshores cal alertar la ciutadania que no val queixar-se, tindrem el sistema de salut que no motivarà prou l’assoliment d’objectius. L’equitat s’haurà aigualit en l’igualitarisme. Al final, els incentius sempre treballen en la seva pròpia direcció. Quan algú interpreta uns resultats d’un sistema com erronis, insuficients o millorables, cal que pensi també que són la conseqüència dels incentius. És a dir, que els incentius dissenyats han conduït a un resultat perfectament equivocat.

Ara tenim davant nostre el repte de la integració social i sanitària al costat de la transformació digital del sistema de salut. No es tracta tant sols de la integració assistencial, ara més que mai cal incentivar l’excel·lència i la qualitat en un entorn d’estancament pressupostari profund. El sistema de pagament dels serveis assistencials que s’ha aplicat d’ençà del decret de 2014 i la compensació dels professionals requereix una revisió en profunditat que no es resoldrà amb tímids ajustos segons entorn socioeconòmic. L’entorn està canviant massa ràpid i la regulació ha de refer-se des dels seus fonaments. Altrament tothom resta avisat, tindrem el resultat d’acord amb  els incentius que hem dissenyat. Som a temps d’escollir entre apostar per la “mediocràcia”, un sistema de qualitat mitjana, o d'excel.lència si incorporem la meritocràcia a les organitzacions sanitàries. Tindrem un resultat justet, o un resultat excel·lent, tot depèn de l’opció escollida.

A selection of:
LI BAI, DU FU, ONO NO KOMACHI, BEATRIU DE DIA, DANTE ALIGHIERI, FRANCESCO PETRARCA, GEOFFREY CHAUCER, AUSIÀS MARCH, PIERRE DE RONSARD, CHRISTOPHER MARLOWE, WILLIAM SHAKESPEARE, JOHN DONNE, FRANCISCO DE QUEVEDO, ANNE BRADSTREET, WILLIAM BLAKE, LORD BYRON, JOHN KEATS, HEINRICH HEINE, ALEKSANDR PUIXKIN, ELIZABETH BARRETT BROWNING, EDGAR ALLAN POE, CHRISTINA GEORGINA ROSSETTI, ALGERNON CHARLES SWINBURNE, THOMAS HARDY, PAUL VERLAINE, ÀNGEL GUIMERÀ, ROBERT LOUIS STEVENSON, W.B. YEATS, PAUL LAURENCE DUNBAR, RAINER MARIA RILKE, EDWARD THOMAS, LOUISE BOGAN, SARA TEASDALE, D.H. LAWRENCE, EDNA ST. VINCENT MILLAY, CARLES RIBA, JOAN SALVAT-PAPASSEIT, VICENTE ALEIXANDRE, JOHN BETJEMAN, W.H. AUDEN, MÀRIUS TORRES, JOSEP PALAU I FABRE, GABRIEL FERRATER, VICENT ANDRÉS ESTELLÉS, JOAN VERGÉS, FELIU FORMOSA, JOSEPH BRODSKY, PERE ROVIRA, MARIA-MERCÈ MARÇAL i JOSEP PEDRALS




Friday, April 8, 2016

Introducing nudging in the law

Nudge and the Law. A European Perspective

Alberto Alemanno is an HEC law professor focused on issues on behavioral policies and regulation. Now he has edited an interesting book. You can check it from this index:

1. The Emergence of Behavioural Policy-Making:A European Perspective

Part I: Integrating Behavioural Sciences into EU Law-Making
2. Behavioural Sciences in Practice: Lessons for EU Rulemakers
3. Nudging and Evidence-Based Policy in Europe: Problems of Normative Legitimacy and Effectiveness
4 . Judge the Nudge: In Search of the Legal Limits of Paternalistic Nudging in the EU

Part II: De-Biasing Through EU Law and Beyond
5. Can Experts be Trusted and what can be done about it? Insights from the Biases and Heuristics Literature
6. Overcoming Illusions of Control: How to Nudge and Teach Regulatory Humility

Part III: The Impact of Behavioural Sciences on EU Policies
7. Behavioural Sciences and EU Data Protection Law: Challenges and Opportunities
8. Behavioural Sciences and the Regulation of Privacy on the Internet
9. EU Consumer Protection and Behavioural Sciences:Revolution or Reform?
10. What can EU Health Law Learn from Behavioural Sciences? The Case of EU Lifestyle Regulation
11. Conduct of Business Rules in EU Financial Services Regulation: Behavioural Rules Devoid of Behavioural Analysis?

Part IV: Problems with Behaviourally Informed Regulation
12 . Making Sense of Nudge-Scepticism: Three Challenges to EU Law ’ s Learning from Behavioural Sciences
13. Behavioural Trade-Offs: Beyond the Land of Nudges Spans the World of Law and Psychology
14. Epilogue: The Legitimacy and Practicability of EU Behavioural Policy-Making

The book deserves time reading it, specially if you are interested in latest trends on nudging and regulation. However, if you don't have enough time, go straight to chapter 10. This is what you should read about implications of nudging on Public Health. He says,
Our previous analysis made a case for more experimentation in behaviourally informed regulation in the EU lifestyle policy. This seems particularly true when examined in light of the limited results attained by self-regulatory schemes led by the food, alcohol, and tobacco industries. While the evidence of what works in terms of behaviour change strategies is limited and too often anecdotal, several success factors have progressively been identified in policy-making.
 These success factors are those we have to check in our close environment and test wether it is worth taking this regulatory approach.

Wednesday, April 6, 2016

Income and health over lifetime

Redistribution from a Lifetime Perspective

An IFS paper says:

Most analysis of the effects of the tax and benefit system is based on snapshot information about a single cross-section of people. Such an approach gives only a partial picture because it cannot account for the fact that circumstances change over life. This paper investigates how our impression of redistribution undertaken by the tax and benefit system changes when viewed from a lifetime perspective.
We find that much of what the tax and benefit system achieves is effectively to redistribute across periods of life and, as a result, it is much less effective at reducing lifetime inequality than inequality at a snapshot.
If distribution of income over lifetimes matters as much as among individuals,  at least in UK, then we have to review certain common place views. I've said that before in this post. Now, Martin Wolf highlights the role of welfare state as a "piggy bank", not only redistributing among people, it reallocates resources among lifetime. "Income is far les unequal over lifetimes than in any given year". Health and education are contributing mostly with benefits when we are old and young respectively.
Unfortunately in our country there is a long way to go, to confirm such intuition.


Friday, April 1, 2016

Obamacare, a book and a documentary

Inside National Health Reform (California/Milbank Books on Health and the Public)

If you want to know the details about how Obamacare was created, the most remarkable book was written by John McDonough five years ago. Today I would like to highlight these statements about the origins:

We decided to focus the first meeting on coverage for all Americans. We conceptualized three avenues we could travel in search of consensus:
• The first we called Constitution Avenue, meaning a radical, systemic shift away from the current system, in which mostAmericans get insurance through their jobs. It could be achieved with a  government-run Canadian-style “single payer” system replacing private insurance with public coverage, sometimes called “Medicare for All.” Or it could be done through the private sector, through the Healthy Americans Act, the scheme devised by Senator Ron Wyden (D-OR), which replaced employer coverage and Medicaid with an individual choice of private plans. Either way, employer-based coverage was eliminated.
• The second we called Independence Avenue, meaning an incremental “go slow” approach to minimize conflict. The federal government could support state high-risk pools to cover those with preexisting conditions, subsidize uninsured lower-income folks, expand Medicaid a bit, and implement limited insurance market reforms. Though it did not come close to universal or even a major expansion, and though it would disappoint and anger many on the Democratic and progressive side because it would fall far short of their expectations, it might get done quickly as a bipartisan measure.
• The third we called Massachusetts Avenue, meaning reform based on the key elements of the near-universal coverage law enacted in Massachusetts in 2006. Those elements include deep and systemic health insurance market reform, a mandate on individuals to purchase insurance, subsidies to make insurance affordable, and an insurance “exchange” to connect people easily with coverage.
After ninety minutes of talking, we wanted them to choose. We would not let them leave without getting a sense of their preferences. “How many want to go down Constitution Avenue?” I asked. Zero hands were raised. “OK, how many want to take Independence Avenue?” Zero hands. “All right, how many want to travel down Massachusetts Avenue?” Of the twenty or so in the room, fifteen hands went up. Impressive, I thought. I noticed the five unraised hands all belonged to business representatives:those from the Business Roundtable, the National Federation of Independent Businesses, the U.S. Chamber of Commerce, the American Benefits Council, and the National Retail Federation. “What’s up?” I asked.“Couldn’t we have a Wisconsin Avenue?” asked Paul Dennett from the American Benefits Council, a large corporate-benefits coalition.“Sure,” I said. “Wisconsin, Pennsylvania, Rhode Island, whatever. You five folks get together, work out what your Wisconsin Avenue looks like, bring it back. Let’s compare it with Massachusetts Avenue, and if that’s where people want to go, that’s what we’ll do.” They came back the following week but had no alternative avenue to propose.
It helps to understand the begining, not the current situation. These statements are in chapter 2, you should follow the whole book to get a clear undestanding. Highly recommended.

And the BBC has recently released a documentary, unfortunately I can't watch it from my location.