シャドーイング練習: Every Major Economic Theory Explained in 20 Minutes - 動画で英語スピーキングを学ぶ

練習モードを選ぶ

各モードは全画面の練習ルームで開きます。

263 文

文が短すぎたり長すぎる場合は、Editをタップして調整してください。

Classical economics picture an economy as a massive machine that runs best when left alone.

This is the core idea behind classical economics.

Born in the 18th century when Adam Smith published The Wealth of Nations in 1776, Smith introduced us to the invisible hand,

the idea that millions of people, each pursuing their own self-interest, unknowingly create order in the economy.

When a baker bakes bread, they're not thinking about feeding society.

They're trying to make money.

Yet their pursuit of profit ensures people get their daily bread.

Classical economists believe that prices, wages, and markets naturally adjust themselves.

If bread becomes too expensive, bakers will see an opportunity to make money.

More bakers enter the market, increasing supply and bringing prices down.

If wages in one industry are high, workers flock there until wages balance out.

This school gave us David Ricardo's theory of comparative advantage.

The idea that countries should produce what they're best at relative to others.

England might be better than Portugal at making both wine and cloth.

But if England is much better at cloth and only slightly better at wine, both countries benefit when England focuses on cloth and Portugal on wine.

The classical economists had one major warning.

Government interference disrupts this natural order.

Tariffs, price controls, and heavy regulations are like throwing a wrench into our economic machine.

Their motto?

Laissez-faire, let it be.

Marxian economics.

If classical economics saw the free market as a harmonious dance, Karl Marx saw it as a battlefield.

Writing in the midst of the Industrial Revolution, Marx wasn't just proposing an economic theory.

He was diagnosing what he saw as a fatal disease in capitalism.

At the heart of Marxian economics is the labor theory of value.

The idea that a product's true value comes from the human labor put into making it.

Picture a worker in a factory making chairs.

In eight hours, they might make ten chairs that sell for $50 each.

Their wage? $80 for the day.

Marx would ask, if the worker created $500 worth of value, why do they only receive $80?

The remaining $420 is what he called surplus value.

essentially profit extracted from the workers' labor.

This leads to Marx's concept of exploitation.

Capitalists, the factory owners, grow wealthy not through their own work, but by pocketing this surplus value.

Marx saw this as an inherent feature of capitalism, not a bug.

Like a pressure cooker building steam, he believed this exploitation would eventually lead to revolution.

Marx introduced the idea of historical materialism, the notion that economic systems naturally evolve through stages.

Just as feudalism gave way to capitalism, he predicted capitalism would inevitably collapse under its own contradictions, leading to socialism and eventually communism.

Game theory.

Imagine economics as a giant chess game, where every move you make depends on what you think others will do.

That's game theory, developed by John von Neumann and later revolutionized by John Nash.

Yes, the beautiful mind guy.

While other economic theories try to predict markets, game theory asks a different question.

How do people behave when their success depends on others' choices?

Let's start with the most famous example, the prisoner's dilemma.

Two criminals are arrested and separated.

Each has two choices, stay silent or betray their partner.

If both stay silent, they each get one year in prison.

If both betray, they each get three years.

But if one betrays while the other stays silent, the betrayer goes free while their partner gets five years.

The rational choice is to betray.

But here's the twist.

If both make this rational choice, they end up worse off than if they'd cooperated.

This simple game explains everything from arms races, to price wars, to climate change.

Companies might all benefit from keeping prices high, but each has an incentive to undercut the others.

Countries might benefit from reducing carbon emissions, but each has an incentive to keep polluting while others cut back.

It's the tragedy of rational self-interest.

Nash's biggest contribution was proving that in any game, there's at least one point where no player can benefit by changing their strategy alone.

The famous Nash equilibrium.

Think about traffic.

We all drive on the right side in America.

Not because it's inherently better, but because everyone else does.

Changing your strategy alone would be disastrous.

Game theory isn't just academic.

It's revolutionized business strategy, international relations, and even biology.

It's used to design auctions, negotiate treaties, and understand everything from dating markets to animal behavior.

It shows us that sometimes the pursuit of self-interest leads to everyone losing.

Neoclassical economics.

In the late 19th century, economists had a revelation.

What if we stopped looking at the economy through the lens of social classes and instead focused on how individuals make choices?

Enter neoclassical economics, which revolutionized how we think about value and price.

Unlike classical or Marxian economists who thought value came from labor,

neoclassicals introduced marginalism, the idea that value comes from the additional satisfaction you get from one more unit of something.

Think about eating pizza.

The first slice, amazing.

The fourth slice, less exciting.

The eighth slice, you might even pay someone to take it away.

This diminishing marginal utility explains why water, essential for life, is cheap, while diamonds, which we can live without, are expensive.

Neoclassicals view the economy as a complex web of supply and demand curves, always seeking equilibrium.

They assume people are rational actors who make decisions to maximize their satisfaction given their limited resources.

Businesses aim to maximize profits.

Consumers aim to maximize utility.

And prices act as signals coordinating this elaborate dance.

Their model of perfect competition envisions many small firms competing with identical products, complete information, and no barriers to entry.

While this rarely exists in reality, it serves as a benchmark for measuring market efficiency and understanding how prices are determined.

Keynesian economics.

The Great Depression shattered the idea that markets always fix themselves.

In 1936, John Maynard Keynes stepped in with a radical new vision.

Sometimes the invisible hand needs a push.

Keynes flipped economic thinking on its head by focusing on aggregate demand, the total spending in an economy.

His key insight?

During a recession, people and businesses get scared.

People save more, businesses invest less.

But here's the paradox.

What's smart for individuals becomes disastrous for the economy.

When everyone saves at once, spending drops, businesses lay off workers, those workers spend less and the economy spirals downward.

This is where Keynes said government must step in.

If businesses won't invest and consumers won't spend, the government should fill the gap, build bridges, hire workers, cut taxes,

do whatever it takes to get money flowing again.

100

This spending creates a multiplier effect.

101

When the government hires a construction worker, that worker buys groceries, the grocery store owner buys new equipment, and so on.

102

with each dollar of government spending generating more than a dollar of economic activity.

103

Keynes' most revolutionary idea?

104

In a depression, thrift isn't a virtue, it's the problem.

105

To him, trying to save your way out of a recession was like trying to lose weight by starving yourself.

106

It might make sense individually, but collectively, it's a recipe for disaster.

107

Supply-side economics.

108

Remember the 1980s?

109

When Reagan promised that tax cuts would pay for themselves?

110

That's supply-side economics in action.

111

While Keynesians focus on boosting demand, supply-siders say, we've got it backwards.

112

Focus on production and the rest will follow.

113

The theory rose to prominence during a time of stagflation, when the economy was both stagnating and experiencing high inflation.

114

Something Keynesian economics struggled to explain.

115

Their big idea is that high taxes and regulations discourage people from producing.

116

Cut taxes, especially on businesses and high earners, and you'll unleash a wave of investment and work effort.

117

The economy grows so much that government actually collects more revenue from lower tax rates.

118

This concept was famously illustrated by economist Arthur Laffer on a napkin, creating what we now call the Laffer curve.

119

Supply-siders believe in trickle-down effects.

120

When the wealthy get tax breaks, they invest in new businesses, create jobs, and boost wages.

121

Like water flowing downhill, the benefits eventually reach everyone.

122

They argue that high marginal tax rates discourage work and investment.

123

After all, why work harder if the government takes most of your additional earnings?

124

But here's where it gets controversial.

125

While supply-side policies led to economic booms, they also coincided with growing deficits and inequality.

126

The 1981 tax cuts didn't pay for themselves as promised.

127

By 1982, Reagan had to raise some taxes to combat growing deficits.

128

Critics say this proves the theory doesn't work.

129

Supporters argue taxes were still too high and regulations too burdensome.

130

Supply-side economics fundamentally changed how we think about taxes and growth.

131

Today, most economists agree that tax rates matter for economic behavior, but debate the size of the effect.

132

The theory remains influential in political debates about tax policy, though often more as a political tool than an economic doctrine, monetarism.

133

In the 1970s, as inflation spiraled out of control, Milton Friedman and the monetarists emerged with a direct challenge to Keynesian dominance.

134

Their message was simple.

135

The real problem isn't managing demand, it's managing money.

136

To monetarists, inflation isn't some mysterious force, it's pure mathematics.

137

Print too much money and each dollar becomes worth less.

138

They summed it up in one famous phrase, inflation is always and everywhere, a monetary phenomenon.

139

Think of it like adding water to soup.

140

The more you add, the less flavorful each spoonful becomes.

141

Friedman argued that government attempts to fine tune the economy often do more harm than good.

142

There's a lag between economic problems and policy responses, like trying to drive a car by looking in the rear view mirror.

143

Instead, he advocated for a simple rule, increase the money supply by a small, steady amount each year.

144

No fancy policies, no government spending sprees, just stable, predictable monetary growth.

145

Monetarists also introduced the concept of the natural rate of unemployment, a baseline level of joblessness that's actually healthy for the economy.

146

Trying to push unemployment below this natural rate through government policy would only lead to inflation, not lasting prosperity.

147

Their solution?

148

Let markets work, keep money stable, and get government out of the way.

149

Development economics.

150

Why do some nations prosper while others stay poor?

151

This isn't just an academic question.

152

It's about billions of people's lives.

153

Development economics tackles this by looking beyond simple models of growth, revealing that prosperity isn't just about capital and labor.

154

It's about the complex web of institutions, culture, and history that shape economic progress.

155

Development economists identified something insidious called poverty traps, vicious cycles where poverty itself prevents growth.

156

Imagine a farmer too poor to buy fertilizer.

157

Without fertilizer, yields stay low.

158

With low yields, they can't save enough to buy fertilizer next year.

159

Now multiply this across millions of people.

160

If you're too poor to save or invest in education, you stay poor.

161

If your country can't build infrastructure, it can't attract business.

162

If corruption is widespread, honest behavior becomes costly.

163

Each problem reinforces the others.

164

But here's where it gets interesting.

165

Development economists found that small targeted interventions can break these cycles.

166

Microfinance programs, pioneered by Muhammad Yunus in Bangladesh, give small loans to entrepreneurs who'd never qualify for traditional banking.

167

Conditional cash transfers, like Brazil's Bolsa Familia, pay families to keep kids in school.

168

Even simple solutions like adding iodine to salt boosted IQ scores and productivity across developing nations.

169

The field has also shattered old myths about development.

170

We used to think poor countries just needed more capital or better technology.

171

But countries like Argentina started rich and fell behind, while others like Singapore started poor and prospered.

172

The difference?

173

Institutions, property rights, rule of law, education systems, and political stability matter more than raw resources or money.

174

This leads to development economics' big lesson.

175

Economic development isn't just about money.

176

It's about transforming societies.

177

Markets alone aren't enough.

178

You need education, healthcare, good governance, and institutions that encourage innovation and enterprise.

179

It's not just about getting richer.

180

It's about building the foundations for lasting prosperity.

181

Austrian School.

182

While other economists were busy building mathematical models, the Austrian School said we were missing the point.

183

Founded by Karl Menger and developed by scholars like Friedrich Hayek and Ludwig von Mises, The Austrians insisted that economics isn't about equations.

184

It's about human action.

185

Their most distinctive idea is their theory of business cycles.

186

Unlike other economists who blame recessions on insufficient demand or monetary mishaps, Austrians point the finger at central banks.

187

When central banks keep interest rates artificially low, it's like giving the economy a sugar rush.

188

Businesses embark on ambitious projects, thinking there's more savings available than there really is.

189

But eventually, reality hits.

190

The sugar rush ends, projects fail, and the economy crashes.

191

The Austrians are also famous for their critique of central planning.

192

Hayek argued that no central planner could ever gather enough information to efficiently run an economy.

193

Think about trying to coordinate what millions of people want for breakfast tomorrow.

194

It's impossible.

195

Markets, through the price system, solve this problem automatically.

196

Every purchase and sale sends signals about what people want and need, creating what they call spontaneous order.

197

This school takes individual freedom seriously.

198

To them, the economy isn't a machine to be managed, but a complex network of human choices that should be left free to evolve naturally.

199

Behavioral economics.

200

What if humans aren't the rational calculators that traditional economics assumes?

201

In the 1970s, psychologists Daniel Kahneman and Amos Tversky started poking holes in our assumptions about human rationality,

202

giving birth to behavioral economics.

203

Their research revealed we're walking bundles of biases and mental shortcuts.

204

We feel the pain of losing $100 more intensely than the pleasure of gaining $100.

205

We'll drive across town to save $5 on a $15 item but won't do the same to save $5 on a $500 item.

206

We buy gym memberships in January, knowing we'll barely use them.

207

Traditional economics can't explain these behaviors, but behavioral economics can.

208

This school introduced the concept of bounded rationality.

209

We don't always make the best decisions, just ones that are good enough.

210

We're influenced by how choices are framed, by what others are doing, and by our emotions.

211

Ever notice how stores mark prices as $9.99 instead of $10?

212

Or how hotels put 80% of guests reuse their towels signs in bathrooms?

213

That's behavioral economics at work.

214

The implications are huge.

215

If people aren't perfectly rational, then markets aren't perfectly efficient.

216

This opens the door for nudges.

217

Subtle changes in how choices are presented that can help people make better decisions while preserving their freedom to choose.

218

New Institutional Economics If traditional economics sees markets as a frictionless machine,

219

New Institutional Economics, NIE, reminds us that in the real world, nothing runs that smoothly.

220

Founded by Ronald Coase and developed by scholars like Douglas North, NIE asks, Why do we need institutions like corporations,

221

laws, and property rights in the first place?

222

Their answer revolves around transaction costs, the friction in economic exchanges.

223

Imagine trying to make a movie without a corporation.

224

You'd need separate contracts with every actor, camera operator, and crew member.

225

You'd have to negotiate every decision.

226

The paperwork alone would kill the project.

227

This is why we create institutions like film companies.

228

They reduce these transaction costs and make complex projects possible.

229

NIE also emphasizes path dependence, how history shapes economic development.

230

Why does Silicon Valley dominate tech?

231

Why do some countries stay poor while others prosper?

232

It's not just about resources or policies.

233

It's about the evolution of institutions over time.

234

A country's legal system, property rights, and business culture create patterns that are hard to change.

235

This school sees economic development as more than just accumulating capital.

236

It's about building better institutions, from reliable courts to functioning markets.

237

Bad institutions can trap countries in poverty, while good ones create the foundation for prosperity.

238

Public Choice Theory What if we analyzed government the same way we analyze markets?

239

Public Choice Theory does exactly that, and the results are unsettling.

240

Founded by James Buchanan and Gordon Tulloch, it applies economic thinking to politics, challenging our romantic notions about democracy and public service.

241

Their key insight?

242

Politicians and bureaucrats aren't selfless public servants.

243

They're rational actors pursuing their own interests, just like anyone else.

244

Just as businesses seek profits, politicians seek votes, and bureaucrats seek larger budgets.

245

A congressman might know a policy is bad for the country, but if it benefits their district, guess how they'll vote?

246

This explains why good policies often fail to pass, while bad ones persist like zombies that just won't die.

247

They identified a crucial concept called concentrated benefits and dispersed costs.

248

Imagine a sugar tariff that costs consumers $20 each per year, but gives sugar producers an extra $20 million.

249

The cost is spread so thin that no individual consumer will bother fighting it, while producers will lobby hard to keep it.

250

This pattern repeats everywhere, from farm subsidies to trade restrictions.

251

It's why democracy often produces policies that harm the majority to benefit powerful minorities.

252

Public choice theorists also expose the myth of the public interest.

253

When a new regulation appears, we assume it's to protect consumers.

254

You dig deeper, and you often find incumbent firms using government power to crush competition.

255

They showed how interest groups capture their regulators, turning watchdogs into guard dogs for the industry.

256

But they don't just criticize.

257

They suggest solutions.

258

Constitutional rules can limit government's ability to play favorites.

259

Sunset clauses can make regulations expire unless actively renewed.

260

Competition between jurisdictions can check government power.

261

If your state tax is too much, you can move.

262

Their message?

263

Democracy needs rules to make self-interest serve the common good.

アプリをダウンロード

流暢に話すために必要なすべて

AI発音採点文ごとに採点

IPA練習すべての音をマスター

単語学習自分の単語帳を作る

単語ゲーム遊びながら覚える

QRをスキャン

Download on theApp Store Get it onGoogle Play

FOR YOU

このレッスンの語彙とスピーキングのポイント

このC1レベルのスピーキングレッスンは、動画「Every Major Economic Theory Explained in 20 Minutes」を教材にしています。繰り返し出てくる語は次のとおりです：economic, economy, theory。この動画には、シャドーイング用の文が263文、単語が2975語あります。音声の長さは20:29です。話す速さは1分あたり約145語で安定しており、シャドーイングしやすいペースです。英語の頻出3,000語に含まれる単語は77%だけなので、語彙は難しめです。

この動画の重要語彙

動画の中で特に難しい単語15語を、発音と意味つきで紹介します。

単語	発音	意味
economist 名詞	/iˈkɑ.nə.mɪst/	経済学者, エコノミスト
rational 形容詞	/ˈɹæʃ(ə)nəl/	合理的
prosperity 名詞	/pɹɑˈspɛɹ.ɪ.ti/	繁栄
capitalism 名詞	/ˈkæp.ə.təlˌɪzm̩/	資本主義
betray 動詞	/bɪˈtɹeɪ/	裏切る, 反逆する
revolutionize 動詞	/ˌɹɛv.əˈl(j)u.ʃəˌnaɪz/	革命を起こす
maximize 動詞	/ˈmæksəmaɪz/	最大化する
slice 名詞	/slaɪs/	切れ, 一片
cloth 名詞	/klɒθ/	布
bureaucrat 名詞	/ˈbjʊɹəkɹæt/	官僚
prosper 動詞	/ˈpɹɑspɚ/	栄える, 賑わう
discourage 動詞	/dɪsˈkɝɪd͡ʒ/	落胆させる, がっかりさせる
equilibrium 名詞	/ɛkwɪˈlɪbɹɪəm/	均衡, バランス
disastrous 形容詞	/dɪˈzæs.tɹəs/	忌まわしい
marginal 形容詞	/ˈmɑː.d͡ʒɪ.nəl/	隅の, 辺境の

動画に出てくる句動詞

単語	意味
fall behind 動詞	遅れる
lay off 動詞	解雇する

この動画の文法

話し手がよく使っている文型を、動画の実際の表現とともに紹介します。

文型	動画での表現
条件文 if + 節, will/would + 動詞 — 条件とその結果	If bread becomes too expensive, bakers will see · If businesses won't invest and consumers won't spend
受動態 be + 過去分詞 — 誰がするかより、何が起きるかに焦点を当てる	are arrested · was famously illustrated · be managed

注意したい発音

話し手はisn't, aren't, can'tなど、短縮形や弱形を43回使っています。聞こえたとおりの短い形で発音しましょう。

「th」の音: cloth /klɒθ/, myth /mɪθ/
「sh」と「zh」の音: rational /ˈɹæʃ(ə)nəl/, revolutionize /ˌɹɛv.əˈl(j)u.ʃəˌnaɪz/, shatter /ˈʃætɚ/, exploitation /ˌɛksplɔɪˈteɪʃn̩/, recession /ɹɪˈsɛʃn̩/
長い単語（アクセントの位置に注意）: economist /iˈkɑ.nə.mɪst/, behavioral /bɪˈheɪvjəɹəl/, prosperity /pɹɑˈspɛɹ.ɪ.ti/, capitalism /ˈkæp.ə.təlˌɪzm̩/, revolutionize /ˌɹɛv.əˈl(j)u.ʃəˌnaɪz/

日本語話者が苦手な音：

/r/ と /l/ の区別 — /l/ は舌先を歯茎につけ、/r/ はどこにもつけない: rational /ˈɹæʃ(ə)nəl/, behavioral /bɪˈheɪvjəɹəl/, revolutionize /ˌɹɛv.əˈl(j)u.ʃəˌnaɪz/, equilibrium /ɛkwɪˈlɪbɹɪəm/, illustrate /ˈɪl.əˌstɹeɪt/
/v/ — /b/ にならないように、上の歯を下唇に当てる: behavioral /bɪˈheɪvjəɹəl/, revolutionize /ˌɹɛv.əˈl(j)u.ʃəˌnaɪz/, evolve /ɪˈvɑlv/, incentive /ɪnˈsɛntɪv/, invisible /ɪnˈvɪzəb(ə)l/
/f/ — 「フ」ではなく、上の歯と下唇で出す: deficit /ˈdɛfəsɪt/, influential /ɪnflʊˈɛnʃəl/

この動画での練習方法

まず声を出さずに動画を最後まで聞き、知らない単語をメモします。
通常の速度で一文ずつシャドーイングし、話し手のリズムに合うまで繰り返します。
自分の声を録音して元の音声と比べます。economist, rational, prosperityなどの単語に特に注意しましょう。

シャドーイングとは？英語上達に効果的な理由

シャドーイング（Shadowing）は、もともとプロの通訳者養成プログラムで開発された言語学習法で、多言語習得者として知られるDr. Alexander Arguelles によって広く普及されました。方法はシンプルですが非常に効果的：ネイティブスピーカーの英語を聞きながら、1〜2秒の遅延で声に出してすぐに繰り返す——まるで「影（shadow）」のように話者を追いかけます。文法ドリルや受動的なリスニングと異なり、シャドーイングは脳と口の筋肉が同時にリアルタイムで英語を処理・再現することを強制します。研究により、発音精度、抑揚、リズム、連音、リスニング力、そして会話の流暢さが大幅に向上することが確認されています。IELTSスピーキング対策や自然な英語コミュニケーションを目指す方に特におすすめです。

シャドーイングのやり方: ステップ別の完全ガイドを読む →

シャドーイング練習: Every Major Economic Theory Explained in 20 Minutes - 動画で英語スピーキングを学ぶ

練習モードを選ぶ

アプリをダウンロード

おすすめ動画

International Trade Explained

14 Brutal Truths I Know at 40 and Wish I Knew at 20

What 50% Unemployment Will Actually Do to the Economy

Not Adam Smith? The Forgotten Economic Genius of Ibn Khaldun

Macroeconomics: Crash Course Economics #5

What is Marxism? (And Why The Outrage is Wrong)

3 game theory tactics, explained

The Five Competitive Forces That Shape Strategy

Everything Valuable from an MBA in 25 minutes

Essence of linear algebra preview

Economic Capital (Easiest Explanation)

How The Economic Machine Works by Ray Dalio