잔규네 : MUSIC's POLITICS

Various Aspects of Demand Curve

Through Micro- and Macro-Economics

수요 곡선에는 여러 가지가 있습니다.

교과서 속 미시와 거시를 망라하여 여러 번 등장하죠.

정리해 볼까요.

스미스나 마샬처럼 개별 경제 주체의 행태를 중시한

학자들은 개별 경제재의 수요를 관찰했습니다.

(공급 곡선과 달리) 수요 곡선은 가격에 반비례하여

가격이 높을수록 낮은 수요, 낮을수록 높다는 것을

알았어요. 마샬이 처음으로 그래프를 그려 보였죠.

가격의 수직축, 수량의 수평축에 우하향하는

곡선 형태가 수학적으로 구현되었답니다.

경제학 교과서에 등장하는 모든 수요 곡선은

이 모형에서 기본적인 논의를 출발시킵니다.

왜 우하향하는가에 대해 고전파는 효용이라는

개념을 제시했습니다. marginal이란 개념도 나왔죠.

1880~90년대에 희한하게도 영국, 프랑스, 독일의

각기 다른 나라에서 각각 연구하던 학자들이 약속이라도

한 것처럼 한계성의 개념을 들고 나와 효용을 해석했죠.

그들에 따르면 수요 곡선이 우하향하는 이유는

한계 효용이 체감하기 때문이었어요. 그들의 눈에

개별 곡선의 점은 효용을 수학화한 것이었거든요.

신고전파 종합을 이끈(추후 그러다 말았음을 인정한)

새뮤얼슨은 현시 선호의 개념을 발전시켜

현대적 시장 이론을 주도하기도 했어요.

개별 수요 곡선이 개별 상품의 행태를 보여주는데

이걸 다 합하면 뭔가 대단한 것이 나오지 않을까…

이런 생각이 나왔어요.

여기서 시장 수요 곡선이 나옵니다.

이론적으로 개별 수요 곡선을 수평으로 합산한 거에요.

이론적으로는. 케인지언이 등장하기 전까지 경제 전체를

거시적으로 바라보고자 했던 고전파 학자들이 이런 식으로

이론 가정을 자주 했다고 해요.

총수요 곡선은 거시 경제학에서 나옵니다.

얼핏 시장 수요 곡선과 비슷해 보이긴 하죠.

하지만 전혀 달라요. 수직축이 물가, 수평축이 GDP입니다.

종속 변수가 달라졌으니 뭔가 신선한 결과가 나왔음직하지만

신기하게도 개별 수요 곡선과 같은 우하향 형태가 나왔어요.

이 총수요 곡선의 우하향 원인은 소비자 효용 원리와 아무런

상관이 없습니다. 크게 두 가지 중요한 이유가 있다 하죠.

첫째, 물가 인하가 금리를 낮추어 투자를 유인한다는 이유..

물가가 내리면 — 가계의 저축이 늘고 — 자금 공급이 늘어

— 금리가 내려가 — 투자가 늘어난다… 이런 스토리에요.

둘째, 환율 인상이 수출을 높여 총생산에 기여한다는 이유..

물가가 내리면 — 금리가 내려 더 좋은 투자처를 찾는 와중에

외환 수요가 늘고 — 자국 통화 평가 절하 = 환율 인상

— 수출이 늘어나 국내 총생산을 높이는… 스토리에요.

(물가가 오르면… 나머지 다 바꾸면 되겠죠.)

하지만 금리니 환율이니 끌어들일 것 없이 단순히

물가가 내리면 한정된 수입에 소비량이 늘어나니

이것만으로도 심플하게 국내 총생산을 늘이겠죠.

(가계 입장에서는 이게 더 확실한 이유..)

어쨌든 여기까지 오면 더 이상 소비자 효용은

국민 경제와 큰 상관이 없는 단계가 되네요.

경제학 전체를 주욱 보면 효용과 선호 등 소비자 이론이

전체에서 약간 동떨어져 따로 논다는 느낌이 들기도 하는데

이런 연장선상에서 음미해볼 수 있을 수도…

아, 참고로.. 본 블로그는 주류 교과서 경제학을 무시하고

폄하하지 않습니다. 주류 말고 비주류도 알아야 한다에 더

가깝죠. 주류 무시하는 비주류 경제학자 아무도 없습니다요.

"공감을 눌러 주시면 큰 힘을 얻습니다"

Ha-Joon Chang: Why You Should Know Economics

경제학자에게 속지 않기 위해, 정치와 정책은 곧 삶에 직결하니까..

https://www.youtube.com/watch?v=3pIFVYRYjks

역사적 제도주의, 네오 맑시즘, 포스트 케인지언, 개발 경제학 등

여러 학파로 분류가 가능한 케임브리지 대학의 장하준 교수님은

노벨상에 가장 근접해 있다고 평가받는 한국의 경제학자입니다.

물론 근접해 있다고만 할 뿐 실제로 받을지는 모르겠어요.

장하준의 업적을 폄하하는 것이 아니라 주류 경제학자들이

이쪽 사이드의 비주류 흐름을 절대로 인정하지 않는 성향이 커서요.

장하준이나 토마 피케티가 받아야 한다면

70년대 말이나 80년대 초쯤 조앤 로빈슨도 이미 받았었겠죠.

(돌아가셨어요. 노벨상은 죽으면 안 줍니다.)

아, 물론 주류 경제학에 속하면서 수상 전망이 밝은

한국인도 얼마든지 계시죠. 미시의 조인구 교수님이라든가..

장하준 교수님이 몇 해 전 영국 왕립 예술 협회에서 강의한 서론 격인 모양인데

동영상 링크로 들어가면 재미있는 애니메이션으로 엮어 놓았습니다.

중간에 2014년에 출간한 ‘장하준의 경제학 강의’에 대한

간략한 소개도 나옵니다. 원제는 Economics: The User’s Guide였죠.

https://www.kyobobook.co.kr/product/detailViewKor.laf?ejkGb=KOR&linkClass=130915&barcode=9788960514065

https://www.amazon.co.uk/Economics-Users-Guide-Pelican-Introduction/dp/0718197038

EU 디스하는 멘트가 나오는 것 보면 이 분의 좌파적 성향을

짐작할 수 있겠으나 다른 어떤 부분은 꽤 보수적이기도 하죠.

번역 자막은 동영상에 달려 있고

아래에는 연설 원문을 게재하니 많이 참고들 하세요.

I’ve tried my best to dispel this wide-spread perception that economics is too complicated for non-economists. Actually it sounds very strange because people have very strong opinions about everything. Iraq War, gay marriage, does God exist, global warming… You all have very strong views on these things, despite not having a degree in theology, not having a degree in energy economics, not having a degree in international relations.

But when it comes to economics, people say, oh yes, it’s for specialists, you know. I don’t know. But why? If you can have a very strong view on Iraq War or Afghanistan without a degree in international relations, you should have a strong view on government economic policy without a degree in economics.

I’d say that this is only because economists have been fantastically successful in making people believe that it is actually a lot more difficult than what it really is. So they will tell you, “Oh you know, I could explain it to you, but then you don’t understand.”

95 per cent of economics is common sense. Of course, it may look too difficult with the use of jargon and mathematics. And even the remaining 5 per cent can be understood at least, in its essence, if not in all technical details, thus if someone bothers to explain it to you in an accessible way.

For example, what is economics? I.e. the ethical foundations of economics, whether you can separate economics and politics, and how different ways of conceptualizing the economy affect the way we see the world, you know. For example, people think that today’s free market economics is a direct descendant of Adam Smith.

But this is not true. In Adam Smith and other so-called classical economists, the economy was conceptualized as being made of classes, not individuals. And the whole theory evolved around the way these different classes with different material interests behave and affect the way capital is accumulated, the economy grows, income is distributed, and so on.

Today in free market economics there are only individuals. When you’ve thought of ten people, oh, isn’t there a class? They say, no, that’s an old Marxists concept. If that’s the case, why do the marketing companies have all these class categories when they do marketing campaign strategy? They will look at groups, a, b, c… c1, c2, to target the advertising according to the type of people.

Now, many economists will tell you that economics is a science in which there is only one right theory. There are at least 9 different major schools of economics and several more if you count minor schools or split the major ones into sub-schools, each with its own unique strength and weaknesses.

And for free market economics alone, you have three different kinds; classical economics, neo-classical economics and Austrian economics. So actually there isn’t one right theory. And my contingent is that we need to all use that diverse approach to economics, in order to fully understand the economy, because they all make certain assumptions, they all have different underlying political and ethical values, they have all sources of different theories about how the economy grows, and so on.

And to make this point, I’ll give you the Singapore problem, or what I call, that life is stranger than fiction. If you read only the financial newspapers like Wall Street Journal or Economist Magazine, it’ll be only told that Singapore succeeded because of its free trade policy and its welcoming attitudes towards foreign investors.

This is partly true. I mean, they did have those things. But you will never be told that Singapore Government owns nearly 90 per cent of all the land. 85 per cent of housing is provided by government-owned housing corporation. And a staggering 22 per cent of GDP is produced by state-owned enterprises.

So in talking of Singapore, I always tell my student, “Look, give me one economic theory. Doesn’t matter what it is, Neo-Classical, Marxist, Austrian, Schumpeterian. Give me one economic theory that can explain Singapore.” There isn’t. So you need to know these different theories to fully understand how a country like Singapore could succeed.

So in this regard my advice is that you should not be a man or a woman with a hammer by leaning only one kind of economic theory, because, whatever that theory is, once you believe that one theory is true, like the man with a hammer, you will start to see everything is a nail. So I’d say that you should get a Swiss knife.

In this dominant economic theory, i.e. up-to-date Neo-Classical theory, people are mainly conceptualized as consumers. And work is considered as, what these economists call, disutility that you have to put up with, so that you can earn money with which you consume goods and services and then derive pleasure or, what they call, utility. That’s your aim — deriving pleasure from consumption. But what happens in our workplace that fundamentally affects us, not just our immediate physical and psychological well-being, but also our identity, our sense of self-worth and our self-fulfillment?

This is why these days in many rich countries a lot of people are very unhappy compared to, say, a couple of decades ago, despite the fact that they have higher income. Why? Because work has become more stressful. But then economists tell you, “No, you should be happy. Britain today has twenty per cent higher income than, say, 1975. Why aren’t you happy?” My book is not just an explanation of economic theories and facts. It’s also a discussion about the role of economics in public life. And in this regard I have three sets of observations to make.

The first one is, “Never trust an economist,” and that includes me. You know, professional economists like to say, “ah, we know what is correct.” No, they don’t have the monopoly of the truth. I’ve already told you that there are 9 different kinds of economic theory. So the right conclusion depends on which economists you talk to.

And I argue that it is entirely possible for people who are not professional economists to have sound judgements on economic issues. I even argue that sometimes their judgements may even be better than those of professional economists, because they may be more rooted in reality and less narrowly focused.

And I argue that indeed the willingness on the part of ordinary citizens to challenge professional economists than other experts, is a foundation of democracy. If you really believe that all we have to do is to listen to the professional consensus of the experts, why do you need democracy? Yes, let self-elected elites appoint each other and run the world, you know. This is why a lot of people are unhappy with European Union.

The second point is the Latin phrase that is apparently written on the walls of the city hall of Gouda, the city in the Netherlands which is famous for cheese. I’m not even going to pretend to speak Latin, and so basically it says, “Listen even to the other side.”

And I argue that this is the attitude that you have to have in debating on the economic issues. I’m not suggesting that you should have no opinion of your own. What I’m trying to tell you is that, given the complexity of the world and given the necessarily partial nature of all economic theories, you should be humble about the validity of your own favorite theory and should keep an open mind about it.

Finally, even while I constantly make reform proposals, I emphasize, “How difficult it is to change the economic reality.” Sometimes the reason is obvious. People who benefit from the status quo want to throw the change by any means, lobbying, bribery, media propaganda and even violence.

The status quo often gets defended even without some people actively being evil. Because the thing about market system is that the rule is one dollar : one vote. So this means that the ability of those with less money to refuse undesirable options given to them is highly constrained.

Also we can be susceptible to beliefs that are against our own interests. The best example is what happened when Barack Obama tried to reform the American medical insurance system. There were all these pictures of all pensioners demonstrating against what they call Obamacare with placards saying things like, “Government, hands off my Medicare.”

Well, except that Medicare is the government programme. This is what the Marxists used to call ‘false consciousness,’ or also known as, the Matrix the movie.

But acknowledging that the difficulty is involved in changing the economic status quo, should not make us give up the fight to create a better economy and better society. Yes, changes are difficult, but in the long run, if enough people fight for something hard enough, many impossible things can happen.

Don’t forget, 200 years ago, if you suggest America should abolish slavery, you’d be branded at least unrealistic and probably the luny. 100 years ago the British Government put women in prison for asking for vote. A lot of women actually said, “Why do we need vote? We have our husbands and brothers to represent our views.

Well, this is why I quote Antonio Gramsci, the Italian Marxist, who once said that we need to have pessimism of the intellect but optimism of the will. Yes, you have to accept difficulties of changing the status quo, but you have to believe that this can be done. And, finally, as Nelson Mandela used to say, it always seems impossible until it is done.