Empirical Tests of Labor Market Separation and Nominal Wage Stickiness in Developing Economies

This lecture delves into advanced empirical strategies for testing fundamental assumptions in development economics, specifically the 'separation test' in household labor supply and the presence of nominal wage stickiness in rural labor markets. It begins by revisiting the challenges of earlier work, like the Benjamin paper, which struggled with unobservable household characteristics. The Lafave and Thomas paper is introduced as an improved approach, leveraging panel data and household fixed effects to address endogeneity concerns. Their key innovation lies in using exogenous changes in household composition, such as the natural aging of children into working age, to identify the impact of labor supply on farm labor demand, thereby providing a more robust test of the separation hypothesis.

The discussion then shifts to the implications of rejecting the separation hypothesis, suggesting that rural labor markets may not be clearing efficiently. The concept of nominal wage stickiness, familiar from macroeconomics, is explored in the context of informal, spot labor markets in developing countries. The lecture highlights Supreme Kaur's work, which empirically tests for nominal wage stickiness using rainfall shocks as exogenous drivers of labor demand in Indian districts. Her findings suggest that wages are indeed sticky downwards, particularly in periods of low inflation, leading to greater negative employment effects during demand downturns.

Further, the lecture presents an experimental approach to studying labor market clearing, again referencing work by Supreme Kaur and co-authors. This experiment involves exogenously shocking labor supply in small villages by temporarily hiring a significant portion of the labor force for off-farm work. The predicted outcomes are discussed: in a competitive market, wages should rise and labor quantity fall, whereas in a rationed market (due to stickiness), wages might not change, and only the quantity of labor supplied would adjust. This experimental design offers a direct way to observe market responses to supply shocks.

Overall, the lecture emphasizes the importance of rigorous empirical methods to test classic theoretical frameworks in development economics. It showcases how innovative data collection (like repurposing data from an iron supplementation study) and sophisticated econometric techniques (panel data, fixed effects, instrumental variables) can provide definitive answers to long-standing questions. The findings challenge the assumption of perfectly clearing labor markets in rural settings, pointing to market imperfections like nominal wage stickiness that have significant implications for employment and household welfare, and highlighting the value of both quasi-experimental and experimental designs in economic research.

"if we have changes in household labor Supply does that kind of affect the amount of Labor demanded on sort of the the household Farms"

"there's unobservable characteristics so like maybe there were people who had like you know really good land those people would have like more kids and they would also have maybe sure they'd have more kids they'd also have like more labor demand"

"they're going to use sort of the the Aging of household members as surely predictable changes in sort of uh you know in your household labor Supply"

"this was data that was collected for a totally different purpose... a long run study of iron supplementation in Central Java"

"if we want to reject separate uh separation we just want to do a joint test that that of all these demographic variables not predicting labor Demand"

"everyone is happy to have their nominal wage go up people do not like their nominal waves to go down"

"if we have nominal stickiness but not real stickiness a little bit of inflation means the real wage can sort of move around a little bit and those markets can clear"

"if your shock is too big then you're no longer makes me feel your favorite Supply shot by too far up"