Survey evidence tells us that stock prices reflect the risks investors associate with long-run technological change. However, there is a shortage of models that can rationalize long-run risks. Unlike the previous literature assuming a fixed number of products, our model allows for new product varieties that appear in the form of new firms which face entry costs and delay in the entry process. The fixed variety model has a significant limitation in translating macroeconomic volatility into asset return volatility. Our model with growing varieties induces endogenous low-frequency fluctuations in productivity driving large, persistent variations in consumption growth and asset prices. It also changes the valuation of assets through the increase in the volatility of the pricing kernel (with a positive long-run component) and leads to higher excess returns. Our model is motivated by a simple recursively identified VAR model containing quarterly US data 1992Q3-2018Q4 with the following list of variables: total factor productivity, output, a measure of firm entry, and the excess return on stocks.

Revolving credit is the prime determinant of short-run household liquidity and comoves positively with product variety and negatively with unemployment. I develop a theory of feedback between revolving credit and product development and examine its ability to explain labor market volatility. Extending the Mortensen–Pissarides model with an endogenous borrowing constraint and free entry of monopolistically competitive firms reproduces stylized facts in the data and amplifies both productivity and financial shocks through mutual causality. Higher debt limits encourage firm entry and raise product variety (the entry channel), and greater variety makes default more costly and thereby raises the equilibrium debt level (the consumption value channel). Though productivity shocks are sufficient to generate higher volatility, financial shocks are essential in approximating the time series patterns of unemployment, vacancies, and revolving credit in the data, and reproduce the rise in unemployment during the Great Recession.

Nine out of the last ten recessions in the United States have been preceded by an increase in the price of oil as noted by Hamilton [Palgrave Dictionary of Economics]. Given the small share of energy in gross domestic product this phenomenon is difficult to explain using standard models. In this paper, I show that firm entry can be an important transmission and amplifying channel for energy price shocks. The results from the baseline dynamic stochastic general equilibrium (DSGE) model predict a drop in output that is two times the impact in a model without entry. The model also predicts an increase in energy prices would lead to a decline in real wages, investment, consumption, and return on investment. Additionally, using US firm level data, I demonstrate that a rise in energy prices has a negative impact on firm entry as predicted by the DSGE model. This lends further support toward endogenizing firm entry when analyzing the effects of energy price shocks.

Business cycle models with sticky prices and endogenous firm entry make novel predictions on the transmission of shocks through the extensive margin of investment. I test some of these predictions using a VAR with model-based sign restrictions. I find a positive and significant response of firm entry to expansionary shocks to productivity, aggregate spending, monetary policy, and entry costs. The estimated response to a monetary expansion does not support the monetary policy transmission mechanism proposed by the model. Insofar as firm startups require labor services, wage stickiness is needed to make the signs of the model responses consistent with the estimated ones. The shapes of the empirical responses suggest that congestion effects in entry make it harder for new firms to survive when the number of startups rises.