(Some quick thoughts hastily written based off some class papers I wrote a while back.)
One dataset that pops to mind is the India Human Development Survey. This is a rich household-level dataset that includes total household monthly income (disaggregated by source) and if I recall right, also tells you what month it is. These are time-intensive to work with, but I imagine a few others datasets like this exist in the world. And you can estimate "income" per month with them.
My guess is you'll get obvious insights from this, like income dropping during cold / dry seasons in more agricultural-dependent villages.
That said, my gut feeling with the policy question is that sending cash transfers sooner is better. A few reasons:
- The book Portfolios of the Poor suggests rural households, especially poor ones, are good at managing their own finances and spreading out their resources over time (or consumption smoothing as economists call it).
- Household debt (not captured in income) may accumulate interest, and interest rates can be exorbitantly high.
- Idiosyncratic shocks (like a family illness) are hard to surveil and predict from afar. So it's hard to implement strategic delays
- Extreme systemic shocks like very harsh droughts / floods may temporarily constrain food / fuel supply reducing effectiveness of cash transfers at that time.
- Households may want to stock up on durable foods like grains or oils ahead of time
- Counterintuitively, giving money while households have high-income may push them over a wealth-threshold that lets them make durable investments (roofs, goats, farm equipment). This may be welfare-enhancing in the long run. I think this goes by the "lump-sum" effect in the cash transfers literature.
Hope this helps. Happy to chat about this more.