Microeconomics and Pricing

Increase or decrease in supply refers to a shift of the entire supply curve, caused by factors other than price. Movement along the same curve (option B) is called extension or contraction of supply, not increase/decrease. These are distinct concepts in supply analysis - shifts vs movements along curves.

In the long run, firms can freely enter or exit an industry. If price is below average total cost, the firm cannot cover all its costs and will eventually exit. Economic profit requires P >= ATC. Options B, C, and D are incorrect because P=MC is profit-maximizing condition (not exit condition), economies of scale reduce costs (encouraging entry), and P > LRAC would attract entry not exit.

The market always moves in trend, except for minor deviations, the stock prices move in trends.

When aggregate demand exceeds aggregate supply in an economy, it creates demand-pull inflation. This occurs because too much money is chasing too few goods, pushing prices up. Cost-push inflation arises from increased production costs, stagflation combines high inflation with stagnant growth, and hyperinflation is extremely rapid inflation typically exceeding 50% per month.

Excess capacity occurs when firms don't produce at the minimum efficient scale. Under perfect competition, free entry and exit forces firms to produce at the minimum point of their long-run average cost curve, eliminating excess capacity. Monopolistic competition inherently creates excess capacity because each firm faces a downward-sloping demand curve and operates with excess capacity to differentiate products.

In a perfectly competitive market, firms are price takers and face a horizontal demand curve at the market price. When a firm doubles its output, the price per unit remains unchanged. Therefore, Total Revenue = Price × Quantity, so doubling quantity exactly doubles total revenue.

Profit maximization occurs where the slope of the profit function is zero (condition B), which mathematically means Marginal Revenue equals Marginal Cost (condition C). For a competitive firm, Price equals Marginal Revenue, so Price = Marginal Cost is also true (condition A). All three conditions represent the same optimization principle from different angles.

Average Revenue equals Marginal Revenue only when the firm faces a perfectly horizontal (perfectly elastic) demand curve. This occurs exclusively in perfect competition where firms are price takers. In monopoly, oligopoly, and monopolistic competition, the demand curve slopes downward, causing AR > MR at all output levels.

A perfectly competitive firm has no control over price (it's a price taker), no control over consumers, and cannot influence market supply through individual decisions. The firm only chooses its output level. Therefore, the correct answer is 'none of the above' - the firm controls production quantity only, not price or consumers.

An ad valorem tax (percentage-based tax) increases the monopolist's marginal cost at every output level. To maximize profit, the monopolist reduces output and raises the price. Both price increase and quantity reduction are proportional to the tax rate. This tax burden is shared between the monopolist and consumers depending on price elasticity.

Price discrimination requires market power (monopoly), ability to segment consumers, and prevent arbitrage. A monopolist can discriminate across any number of buyer groups - two, three, four, or several. The question asks for the most general correct statement. 'Several buyers' (option D) encompasses all specific numbers and is therefore the correct choice.

Under monopolistic competition, firms have some market power due to product differentiation but still face competition. The demand curve is highly elastic (large elasticity) because close substitutes are available, but not perfectly elastic like in perfect competition. A small price increase causes significant quantity loss as consumers switch to differentiated competitors.

Like all profit-maximizing firms regardless of market structure, a monopolistically competitive firm produces where Marginal Revenue equals Marginal Cost (MR = MC). At this output level, the firm maximizes its profit or minimizes its loss. The other options (MR > MC would mean underproducing, MR < MC would mean overproducing) represent suboptimal decisions.