The macro environment: growth, inflation, interest rates and exchange rates

The first ten lessons focused on microeconomics: decisions by individual firms, consumers and markets. But every firm also operates in a macroeconomic environment it cannot control. Recessions cut demand across industries; inflation raises input costs and changes how customers behave; interest rates determine the cost of capital and the value of long-lived investments; exchange rates move the competitiveness of exporters and the margins of importers; and trade policy can change the economics of a supply chain overnight. Managers do not need to forecast these variables better than professional economists, which is very hard, but they do need to understand how they work, how central banks respond, and how their own business is exposed. This lesson gives that understanding and shows how to build macro scenarios into plans.

Output, growth and the business cycle

Gross domestic product measures the market value of final goods and services produced in an economy in a period. It can be measured as the sum of spending, consumption plus investment plus government purchases plus net exports; as the sum of incomes, wages, profits, rents and interest; or as the sum of value added by each industry. The Bureau of Economic Analysis publishes GDP quarterly, with advance, second and third estimates. Real GDP adjusts for price changes and is the main measure of output; real GDP per person is a rough measure of living standards. Over long periods, real GDP grows because of more workers, more capital per worker and better technology and organization, which economists call total factor productivity. American productivity growth has been faster than that of most other advanced economies since the 2000s, helped by technology and business investment.

In the short run, output fluctuates around its potential in the business cycle. Expansions are periods of rising output and employment; recessions are periods of falling output, dated in the United States by the Business Cycle Dating Committee of the National Bureau of Economic Research. The output gap, the difference between actual and potential output, is a key input to monetary policy: a positive gap tends to raise inflation, a negative gap to lower it. Unemployment rises in recessions and falls in expansions, as described by Okun's law, which links a percentage point of output gap to roughly half a percentage point of unemployment.

Industries differ greatly in their sensitivity to the cycle. Grace's grocery business is defensive: people keep eating in recessions, though they trade down to cheaper brands and private label. Daniel's automotive and industrial parts business is cyclical: vehicle and equipment purchases can be postponed, so Northfield's volumes fall sharply in downturns, and operating leverage, the high share of fixed costs discussed in Lesson 4, amplifies the effect on profit. Owen's energy business depends on commodity prices driven by the global cycle. Hana's health care demand is stable, but government budgets that fund it are cyclical. Kestrel's software sales depend on corporate budgets, which tighten in recessions, though tools that cut costs can sell well then. Knowing where a business sits helps managers plan capacity, inventory and financing.

Inflation

Inflation is a sustained rise in the general price level. The Bureau of Labor Statistics measures it with the consumer price index, which tracks the cost of a basket of goods and services; the Federal Reserve's preferred measure is the personal consumption expenditures price index published by the Bureau of Economic Analysis. The Fed targets 2 % inflation over the longer run as part of its dual mandate of maximum employment and stable prices. Inflation can be driven by demand, when spending outpaces the economy's capacity; by costs, when energy, food or wage shocks raise prices; and by expectations, when firms and workers build anticipated inflation into prices and wages. Expectations matter because they can make inflation self-sustaining, which is why central banks guard their credibility carefully.

Inflation surged in 2021 and 2022 as the economy reopened, supply chains strained and energy prices spiked, peaking at 9.1 % on the consumer price index in June 2022 before falling back toward the target. In 2026, energy prices rose again: in September 2026, consumer prices were 3.7 % higher than a year earlier, with energy up 20.4 %, while core inflation, excluding food and energy, was 2.6 %. Separating a temporary energy shock from broader inflation is exactly the judgment central banks must make.

For managers, inflation creates several challenges. Input costs rise at different rates, so margins shift between products. Customers become more price-sensitive and more likely to trade down. Contracts that are fixed in nominal terms lose real value for the seller, which is why long-term supply contracts often include indexation or escalation clauses. Wage negotiations become harder. And because accounting statements are in nominal terms, inflation can flatter reported profits through inventory gains and understate the cost of replacing assets. Daniel learned this in 2022, when Northfield's fixed-price contracts with some customers lost money as steel prices jumped; the company now includes steel surcharges indexed to a published price.

Real and nominal interest rates

The nominal interest rate i is what lenders quote; the real interest rate r is the return after inflation, and π^e is expected inflation. The Fisher equation, named after Irving Fisher, links them. Real rates matter for investment decisions: a 6 % loan with 4 % expected inflation is cheaper in real terms than a 5 % loan with 1 % inflation. When managers discount cash flows, they must be consistent, using nominal rates with nominal cash flows that include inflation, or real rates with real cash flows. Mixing them is a common and costly mistake in capital budgeting.

Monetary policy and central banks

The Federal Reserve conducts monetary policy through its Federal Open Market Committee, which sets a target range for the federal funds rate, the rate at which banks lend reserves overnight. The committee meets eight times a year and publishes economic projections of its members four times a year. Changes in the target range pass through to the prime rate, credit cards and adjustable-rate loans quickly, and to longer-term rates such as 30-year mortgage rates through expectations. Higher rates cool demand by making borrowing more expensive, raising the value of the dollar and reducing asset prices; lower rates do the opposite. The effects on inflation take about 18 months to two years to work through fully.

After a series of cuts in 2024 and 2025 as inflation fell, the Federal Reserve held the range at 3.75 % to 4.00 % on 28 October 2026 by a vote of 10 to 2, with the two dissenting members preferring an increase because of the energy-driven rise in inflation. On the same day the Bank of Canada raised its policy rate to 2.50 %. American short-term rates therefore remain well above Canadian ones, which supports the American dollar against the Canadian dollar and matters for firms that trade across the border.

A simple guide to how central banks respond is the Taylor rule, proposed by John Taylor in 1993. It suggests setting the policy rate equal to the neutral real rate plus inflation, plus half the gap between inflation and the target, plus half the output gap. Central banks do not follow any rule mechanically, but the Taylor rule captures the direction of their responses and helps managers anticipate whether rates are likely to rise or fall.

# Taylor rule, real rates and the effect of rates on project value
def taylor(neutral_real, inflation, target, output_gap):
    return neutral_real + inflation + 0.5 * (inflation - target) + 0.5 * output_gap

for label, infl, gap in [('Inflation at target, no gap', 2.0, 0.0),
                         ('Energy shock: inflation 3.1 %, small negative gap', 3.1, -0.5),
                         ('Recession: inflation 1.5 %, gap -2 %', 1.5, -2.0)]:
    print(f"{label:50s} suggested policy rate {taylor(0.75, infl, 2.0, gap):5.2f} %")

# Real interest rate from the Fisher equation
for nominal, expected_inflation in [(6.0, 4.0), (5.0, 1.0)]:
    real = (1 + nominal / 100) / (1 + expected_inflation / 100) - 1
    print(f"Nominal {nominal:.1f} % with expected inflation {expected_inflation:.1f} % -> real {real:.2%}")

# A long-lived project is sensitive to the discount rate
cash, years = 10.0, 20          # 10 million dollars a year for 20 years, after a 100 million dollar outlay
for rate in (0.06, 0.07, 0.08, 0.09):
    pv = sum(cash / (1 + rate) ** t for t in range(1, years + 1))
    print(f"Discount rate {rate:.0%}: present value {pv:6.1f} million, NPV {pv - 100:6.1f} million dollars")

Inflation at target, no gap                        suggested policy rate  2.75 %
Energy shock: inflation 3.1 %, small negative gap  suggested policy rate  4.15 %
Recession: inflation 1.5 %, gap -2 %               suggested policy rate  1.00 %
Nominal 6.0 % with expected inflation 4.0 % -> real 1.92%
Nominal 5.0 % with expected inflation 1.0 % -> real 3.96%
Discount rate 6%: present value  114.7 million, NPV   14.7 million dollars
Discount rate 7%: present value  105.9 million, NPV    5.9 million dollars
Discount rate 8%: present value   98.2 million, NPV   -1.8 million dollars
Discount rate 9%: present value   91.3 million, NPV   -8.7 million dollars

The code shows how a Taylor rule suggests higher rates in an energy shock that lifts inflation above target, even when output is slightly below potential, and lower rates in a recession, with a neutral real rate assumed at 0.75 %. It then shows why interest rates matter so much for capital-intensive firms: a 20-year project that is clearly worthwhile at a 6 % discount rate turns slightly negative at 8 % and destroys value at 9 %. Owen's capital budgeting at Prairie Ridge and Daniel's equipment purchases at Northfield both depend on this sensitivity.

Exchange rates

The exchange rate is the price of one currency in terms of another. The American dollar is the world's main reserve and trading currency, and its value against the euro, the yen, the Canadian dollar, the Mexican peso and the Chinese renminbi affects American firms' competitiveness and the dollar value of foreign earnings. In the short run, exchange rates are driven by interest rate differences, commodity prices and risk sentiment, with the dollar often strengthening in global crises as investors seek safety; over long periods, they tend toward purchasing power parity, the rate that equalizes the cost of a basket of goods, though deviations can persist for years. A stronger dollar helps importers and Americans traveling abroad and hurts exporters and multinationals that report foreign profits in dollars.

Firms face three kinds of currency exposure. Transaction exposure arises from specific receivables and payables in a foreign currency. Translation exposure arises from converting foreign subsidiaries' statements into the reporting currency. Economic exposure, the broadest and most important, is the effect of exchange rates on a firm's competitive position and future cash flows, even if it has no foreign currency transactions at all, for example because a domestic competitor imports from a country whose currency has weakened.

# How the exchange rate moves margins for an exporter and an importer
def exporter_margin(fx, price_usd=100.0, cost_cad=105.0):
    revenue_cad = price_usd * fx            # fx = Canadian dollars per American dollar
    return (revenue_cad - cost_cad) / revenue_cad

def importer_margin(fx, price_cad=150.0, cost_usd=80.0, other_cad=25.0):
    cost = cost_usd * fx + other_cad
    return (price_cad - cost) / price_cad

print(" CAD per USD   exporter margin   importer margin")
for fx in (1.25, 1.30, 1.35, 1.40, 1.45):
    print(f"   {fx:5.2f}        {exporter_margin(fx):7.1%}          {importer_margin(fx):7.1%}")
# Partial hedge: the importer locks in 60 % of next year's purchases at 1.35
spot = 1.45
blended = 0.6 * 1.35 + 0.4 * spot
print(f"Importer margin at spot {spot} with a 60 % hedge at 1.35: {importer_margin(blended):.1%} (unhedged {importer_margin(spot):.1%})")

 CAD per USD   exporter margin   importer margin
    1.25          16.0%            16.7%
    1.30          19.2%            14.0%
    1.35          22.2%            11.3%
    1.40          25.0%             8.7%
    1.45          27.6%             6.0%
Importer margin at spot 1.45 with a 60 % hedge at 1.35: 9.2% (unhedged 6.0%)

The code illustrates the opposite exposures of an exporter and an importer, using Northfield's Canadian plant and Fairway's produce imports, which are priced in American dollars, as examples; the exchange rate is expressed as Canadian dollars per American dollar, so a higher number is a stronger American dollar. For American firms the logic is the same in reverse: a stronger dollar squeezes exporters whose costs are in dollars and helps importers. Hedging with forward contracts smooths the effect for a year or so, as the last line shows, but cannot protect against a lasting change in the exchange rate; for that, firms adjust sourcing, pricing and where they produce.

Trade policy

Trade policy has become a major source of business risk. Since 2025, the United States has imposed tariffs under section 232 of the Trade Expansion Act of 1962 on steel, aluminum, automobiles and parts, and softwood lumber, among other products, and trading partners including Canada responded with retaliatory tariffs on some American goods. The United States–Mexico–Canada Agreement, which kept most trade between the three countries tariff-free, came up for its joint review on 1 July 2026. The United States did not agree to extend the agreement's term, so it now moves to annual reviews while remaining in force until 2036 unless the parties decide otherwise. For managers, this means planning for a range of trade outcomes rather than a single forecast.

The economics of tariffs follow from the supply and demand tools of Lessons 2 and 5. A tariff raises the price of imports, protecting domestic producers but raising costs for buyers, including domestic manufacturers that use the imported goods as inputs. Who bears the tariff depends on elasticities: if buyers have few alternatives, they pay most of it; if foreign sellers have few other markets, they absorb part by cutting prices. For integrated supply chains like North American automotive manufacturing, in which parts cross the border several times before a vehicle is finished, tariffs compound at each crossing. Daniel's team mapped every Northfield part that crossed the border and its tariff status, then evaluated moving some machining to the plant on the other side of the border, sourcing steel domestically and sharing tariff costs with customers through surcharge clauses.

Building macro scenarios into plans

Because macroeconomic forecasts are uncertain, managers are better served by scenarios than by point forecasts. A good scenario set covers a base case and two or three plausible alternatives, such as a recession, an inflation shock or a trade disruption, each with consistent assumptions about growth, inflation, interest rates, exchange rates and the firm's specific drivers. The firm then tests its plan under each scenario and identifies early indicators, such as purchasing managers' indexes, yield curves, central bank statements and commodity prices, that signal which scenario is unfolding. Lesson 12 applies this approach to Cedarline Outdoor's capacity decision.