عرضه، تقاضا و قیمتSupply, demand and price

Cause and effect, and the mixed conditional in argument

توضیح اقتصادی یعنی زبان علت‌ومعلول زیر فشار. زنجیره: به‌جای تکرار because از طیفی از افعال علّی استفاده کن — X leads to Y، X results in Y، Y stems from X، X drives Y، X is driven by Y، X accounts for Y. به جهت دقت کن: results in و leads to از علت به معلول می‌روند؛ stems from و is driven by از معلول به علت. اشتباه‌گرفتن جهت، استدلالت را وارونه می‌کند. کمّی‌کردن تغییر: prices rose sharply / slightly / by a third / from 40 to 55؛ a sharp rise، a slight fall، a steady increase. با فعل قید بیاور و با اسم صفت — rose sharply، a sharp rise — هرگز «rose sharp». خلافِ واقع: اینجاست که شرط ترکیبیِ درس ۱ در استدلال واقعاً کار می‌کند. «If I had not raised the price, I would be selling at a loss now» — شرط گذشته، نتیجهٔ حال. «If demand had fallen, we would have closed» — شرط گذشته، نتیجهٔ گذشته. خلافِ واقع راهی است که با آن از یک تصمیم دفاع می‌کنی: می‌گذارد جهانی را توصیف کنی که رخ نداد.

Economic explanation is cause-and-effect language under pressure. THE CHAIN: use a range of causal verbs rather than repeating because — X leads to Y, X results in Y, Y stems from X, X drives Y, X is driven by Y, X accounts for Y. Note the direction: results in and leads to run cause → effect; stems from and is driven by run effect → cause. Getting the direction wrong reverses your argument. QUANTIFYING CHANGE: prices rose sharply / slightly / by a third / from 40 to 55; a sharp rise, a slight fall, a steady increase. Use the adverb with a verb and the adjective with a noun — rose sharply, a sharp rise — never "rose sharp". THE COUNTERFACTUAL: this is where the mixed conditional from lesson 1 does real work in argument. "If I had not raised the price, I would be selling at a loss now" — past condition, present result. "If demand had fallen, we would have closed" — past condition, past result. Counterfactuals are how you defend a decision: they let you describe the world that did not happen.