Labor Market graph mistakes

15 ways students lose points on this diagram, each taken from a worked free-response scenario. Every entry names the reasoning that causes the error, not just the error, because the wrong answer is usually a sensible thought applied to the wrong curve.

1. 01

   Apple Harvest Wages

   The mistake. Many students also shift labor supply right, reasoning that the higher wage will attract more pickers into the orchards. The wage increase is the RESULT of the demand shift, and workers responding to it move ALONG the existing supply curve; nothing changed how many people were willing to work at any given wage.

   Draw this instead. Labor demand (DL) shifts right.

   Exam tip. Whenever the stem changes the price of the OUTPUT, go straight to MRP = MP x P and shift only labor demand; the wage is an outcome you read off the new equilibrium, never a cause.

   Try this one on a live graph
2. 02

   Frostvale Immigration Reform

   The mistake. A common wrong answer shifts labor demand right too, on the logic that more immigrants means more customers and therefore more construction. This graph is one industry's labor market, not the whole economy: labor demand here is MRP, and the stem explicitly freezes both construction output prices and productivity, so MRP cannot move.

   Draw this instead. Labor supply (SL) shifts right.

   Exam tip. Sort every stem by who it acts on: if it changes how many PEOPLE are willing to work, it is a labor supply determinant; if it changes what a worker adds to the FIRM's revenue, it is labor demand.

   Try this one on a live graph
3. 03

   Coal Country Wages

   The mistake. Students often shift labor supply left as well, picturing miners quitting once pay drops. Workers leaving because the wage fell is a movement along an unchanged supply curve, and moving that curve on the graph makes the answer wrong even though labor demand was shifted correctly.

   Draw this instead. Labor demand (DL) shifts left.

   Exam tip. A leftward labor demand shift drives wage and employment DOWN together; if your finished graph shows the wage moving one way and employment the other, you shifted the wrong curve.

   Try this one on a live graph
4. 04

   Warehouse Automation Tools

   The mistake. Many students shift labor demand LEFT because the stem mentions automation and they assume machines replace workers. Here the devices are held BY the workers and raise each worker's output per hour, so capital is a complement that raises MRP, not a substitute that displaces labor.

   Draw this instead. Labor demand (DL) shifts right.

   Exam tip. Ask one question of any technology stem: does the machine do the worker's job (substitute, labor demand left) or make the worker better at their job (complement, labor demand right)? The wording of the stem always tells you which.

   Try this one on a live graph
5. 05

   Rival Industry Pay Surge

   The mistake. A frequent error is shifting labor demand left because employment ends up lower, with students reasoning that trucking firms 'hire fewer drivers.' Firms hiring fewer drivers here is a movement UP along an unchanged labor demand curve as the wage rises; MRP itself depends on freight prices and productivity, which the stem freezes.

   Draw this instead. Labor supply (SL) shifts left.

   Exam tip. Wage UP with employment DOWN can only come from a leftward supply shift, so let that combination confirm your answer before you move on.

   Try this one on a live graph
6. 06

   Fading Fashion Demand

   The mistake. Students frequently shift labor supply left as well, treating the resulting layoffs as workers leaving the market. Sewers losing jobs is the fall in quantity of labor demanded and a movement along the supply curve to a lower wage, not a change in how many people are willing to sew at any given wage.

   Draw this instead. Labor demand (DL) shifts left.

   Exam tip. Labor is a DERIVED demand: a change in consumers' taste for the product reaches the labor market only through the output price inside MRP, so it is always a labor demand event with supply held fixed.

   Try this one on a live graph
7. 07

   Childcare and Factory Jobs

   The mistake. Students often shift labor demand right instead, reasoning that with more available workers the plants can produce more. Labor demand is the MRP schedule, which depends only on productivity and the output price; both are frozen here, and firms hiring more workers is a movement DOWN along the unchanged demand curve as the wage falls.

   Draw this instead. Labor supply (SL) shifts right.

   Exam tip. Barriers to showing up for work (childcare, commuting costs, licensing rules, visa limits) are always labor SUPPLY determinants, no matter which side of the market the news story is written about.

   Try this one on a live graph
8. 08

   Machinists Reach Retirement

   The mistake. A common wrong answer shifts labor demand left, reading 'workers leaving' as the industry shrinking. The tool shops still value each machinist exactly as much as before, since parts prices and productivity have not changed; what shrank is the number of people available to hire, which is a supply-side change.

   Draw this instead. Labor supply (SL) shifts left.

   Exam tip. When a stem mentions that replacements are not being trained, it is telling you the supply shift is permanent rather than a temporary dip, so shift the whole curve left instead of sliding along it.

   Try this one on a live graph
9. 09

   Self-Checkout Kiosks

   The mistake. Many students shift labor demand RIGHT, borrowing the rule that new technology raises productivity and therefore MRP. That rule applies when the machine makes each worker more productive, but this kiosk replaces the worker rather than assisting one, and the stem holds cashiers' own productivity constant, so only the substitution effect operates.

   Draw this instead. Labor demand (DL) shifts left.

   Exam tip. For any resource-price stem, first classify the other input as substitute or complement: a cheaper SUBSTITUTE shifts labor demand left, while a cheaper COMPLEMENT shifts it right.

   Try this one on a live graph
10. 10

    New Hospitals Open

    The mistake. Students often shift labor supply right here, hearing 'new hospitals' as 'more nursing jobs' and treating jobs as supply. Jobs are positions employers want to fill, which lives on the demand side; labor supply counts PEOPLE willing to work, and the stem freezes that number explicitly.

    Draw this instead. Labor demand (DL) shifts right.

    Exam tip. More firms hiring from the same worker pool is the labor-market twin of new sellers entering a product market, except it shifts DEMAND, not supply, so wage and employment both rise.

    Try this one on a live graph
11. 11

    Mine Hazard Report

    The mistake. Students frequently shift labor demand left, assuming bad news about an industry must hurt the firms. The mines can still sell copper at the same world price and each miner still digs the same amount, so MRP is untouched; the news changed only what workers require to accept the job.

    Draw this instead. Labor supply (SL) shifts left.

    Exam tip. This is the compensating differential: unpleasant or dangerous jobs pay MORE precisely because labor supply to them sits farther left, so a rising wage on your graph confirms the answer rather than contradicting it.

    Try this one on a live graph
12. 12

    Auto Plant Closes

    The mistake. A common error is shifting labor demand left because the stem describes a plant closing and job losses, which students read as a shrinking economy. The closure happened in the automobile market; on this graph the axis is warehouse loading, where nothing changed about the output price or productivity, so only the pool of available workers moved.

    Draw this instead. Labor supply (SL) shifts right.

    Exam tip. Read the axis label before you touch a curve: events in a NEIGHBORING industry usually reach your market through workers moving between jobs, which is always a labor supply shift.

    Try this one on a live graph
13. 13

    Grape Price and Visa Rule

    The mistake. The most common wrong answer treats both outcomes as determinate, usually 'wage up, employment down,' because students latch onto the visa rule as the headline event and quietly ignore the grape price. When two curves move, only the variable that both shifts push the same way has a determinate direction; here that is the wage, and employment must be stated as indeterminate. A second error is shifting only labor demand, on the reasoning that the wage increase will pull the missing workers back, but workers responding to a higher wage move ALONG the new supply curve rather than undoing the shift.

    Draw this instead. Labor demand (DL) shifts right and Labor supply (SL) shifts left.

    Exam tip. On any combined-shift stem, draw both curves first, then test each outcome variable separately: if the two shifts push it the same way, commit to a direction, and if they oppose, write the word 'indeterminate' and name the relative size of the shifts as what it depends on.

    Try this one on a live graph
14. 14

    Room Rates and Licensing Repeal

    The mistake. Students overwhelmingly answer that the wage falls AND employment falls, treating the resort news as the real story and the licensing repeal as a detail, which loses the point because employment cannot be signed here. A related error is shifting labor supply left instead of right, reasoning that people will avoid an occupation whose pay is dropping; the lower wage is an outcome of the two shifts, and workers reacting to it move along the new supply curve rather than shifting it again.

    Draw this instead. Labor demand (DL) shifts left and Labor supply (SL) shifts right.

    Exam tip. When the two shifts fight over one variable, sketch it twice, once with a tiny supply shift and once with a huge one, and if employment lands on opposite sides of the original quantity, say 'indeterminate' in words rather than hoping the grader reads your drawing.

    Try this one on a live graph
15. 15

    New Jigs, New Housing

    The mistake. The signature wrong answer is that employment rises and the wage rises, because students remember that higher productivity raises MRP and therefore pay, and they never weigh the housing shift against it. With both curves moving right the quantity axis is settled and the wage is not, so claiming a direction for the wage is exactly the error the question is testing. A separate trap is shifting labor demand LEFT because the jigs sound like automation; these jigs make each worker faster rather than doing the worker's job, so they are a complement that raises MRP.

    Draw this instead. Labor demand (DL) shifts right and Labor supply (SL) shifts right.

    Exam tip. Memorize the shortcut for same-direction shifts: when both curves move the same way, the quantity outcome is determinate and the price outcome, here the wage, is the indeterminate one, so spend your writing on naming what the wage depends on rather than guessing it.

    Try this one on a live graph