Due to the Coronavirus pandemic my spring semester face-to-face courses could not meet on campus. I therefore recorded what we would normally have done in class including the clicker quiz questions, yellow page questions, and short lectures, and posted them online. There are also two former lectures recorded on snow days. I am making them available to my online summer sections. I hope you find them helpful. Unit 1: Markets are Efficient, Except . . . Introduction to Microeconomics 1a - The Class and the Math 1b - The 5Es of Economics 1c - Making Choices: Scarcity and Budget Lines 1d - Making Choices: Production Possibilities and Benefit-Cost Analysis 2a - Market Economies and Trade 3a - Demand 3b - Supply 3c - Market Equilibrium and Efficiency 5a - Gov't Interference in Markets and Market Failure (Negative Externalities) 5b - Market Failure Con't: Positive Externalities and Public Goods   UNIT 2: Elasticity, Consumer Choice, and Costs 4a - Price Elasticity of Demand and Tax Incidence 4b - Other Types of Elasticity 6a - Consumer Decisions: Utility Maximization 7a - Econ. Profit and the Production Function 7b - Production Costs in the Short Run 7c - Production Costs in the Long Run   Unit 3: Are Businesses Efficient? Product Markets and Efficiency 8/9a - Pure Competition: Characteristics and Short Run Equilibrium 8/9b - Pure Competition: Long Run Equilibrium and Efficiency 10a - Monopoly: Characteristics and Short Run Equilibrium 10b - Monopoly: Long Run Equilibrium, Price Discrimination, and Regulation 11a - Monopolistic Competition: Are Businesses Efficient? 11b - Oligopoly: Are Businesses Efficient? and Game Theory   Unit 4: Labor and Efficiency: Resource Markets, Inequality, and Immigration 12a - Demand For Resources 13a - Wage Determination: Labor Markets 20a - Income Inequality and Discrimination 22a - Immigration