Title: Marital Decline: The Role of House Prices and Parental Coresidence

Abstract: Over the past 40 years in the U.S., marriage rates havedeclined significantly while parental coresidence among young adults hasincreased sharply, especially among the non-college educated. At the same time, rising house prices have outpacedincome growth, decreasing housing affordability. This paper analyzes how theserising prices influence coresidence and marriage decisions. I first present astylized model illustrating the dual impact of higher house prices: theyencourage marriage due to economies of scale but also lead to more individualsliving with parents, decreasing their participation in the marriage market.Then, I develop a quantitative life-cycle model of household formation(marriage and divorce) and housing choices (coresidence, renting, and buying).The model economy is characterized by equilibrium in the marriage and housingmarkets and is calibrated to the 2019 U.S. economy. I use the model for twoexercises. First, I quantify the role of house prices on the marital declinebetween 1980 and 2019. I find that house prices explain around 30% of thedecline in marriage. Additionally, the model can account for the larger drop inmarriage among the non-college educated. Second, I evaluate the effect ofhousing policies and find that a 10% rental subsidy financed by higher taxescan reduce parental coresidence among young adults by 3.3 percentage points,and increase their marriage rates by 1.5 percentage points.

Title: Selling on Recommender Platforms: DemandBoost versus Customer Migration

Abstract: We develop a model to study the pricing andwelfare implications of recommender platforms---i.e., platforms that providerecommendations about products that match a consumer's preference. Sellersoffer their product on the platform and on their direct channel. Consumers notonly have access to (some) seller's direct channel offerings and the platform'srecommendation, but they can also engage in costly sequential search on theplatform to discover additional products.

 We highlight novel trade-offs that occurbecause sellers are in an advantageous position when they are being recommendedbut in a disadvantages position when they try to appeal to consumers via theirdirect channel (which is not based on a recommendation).  As a result, ifthe platform raises its fee, inducing sellers to assign greater weight to theirdirect channel sales, the sellers' equilibrium price can fall. Likewise,improving the recommendation algorithm can also lead to a reduction of the equilibriumprice if the platform's commission fee is too large.

 We further endogenize the platform'scommission fee and show that the price level decreases as recommendationsimprove if search costs are high and increases if search costs are small. Wealso show that regulating data collection by the platform to reduce the qualityof recommendations raises consumer surplus if search costs are small, but canlower consumer surplus otherwise. Finally, we identify adverse effects ofcapping platform fees and of facilitating disintermediation.