6a. Marginal Rate of Substitution and Marginal Utility (with Calculus)

[Visillis]

this makes everything a lot clearer! thanks from Belgium!

[publicanimal]

It makes more sense when I watch it on YouTube then when I see it in class.

[lotraven]

Thanks a lot.

[gillou800]

Hey, have you some videos for macroeconomics?

[PutaMadreheh]

Thank-you very much kind sir.

[macrocec]

of course you earned a thumbs uo buddy, great vid

[Dsarge21]

This guys smile before the videos start get me every time

[IGOTCREAM]

could you explain the differentiation? are you treating as a partial derivative?

[intromediateecon]

@IGOTCREAM There are partial derivatives and regular derivatives in the video.

df/dx is a regular derivative. At 0:39. I wrote it as a partial, but those d's should be standing up straight.

du/dx and du/dy (the marginal utilities) are partial derivatives, and they come in through the chain rule's total differentiation.

I hope that clarifies.

[renada89]

Really good explanation, but have you done anything about deriving Marginal Revenues?

[intromediateecon]

@renada89 Thanks! And, yes I have. That's video "29a" on my channel. It is under my "monopoly and imperfect competition playlist." You may find it more easily by going to my video web page (link in the description of this video).

[debomiralha]

I liked it...but would be nice if you used number to perform the diferentiation!It would be easier to understand!!but still great lecture!!

[intromediateecon]

@debomiralha Thanks for the suggestion. Given that you are the third one to request something like this in addition to what I have already done in the video, I'll put this request on my "to do" list.

[mehdiand1job]

this need a simple exercice or something like that :)

[intromediateecon]

@mehdiand1job Lecture 6 (the non-calculus version of this one) relies on a numerical example. I don't know if that's what you mean by a simple exercise, but you may want to check out that video.

[thienthan07]

Could you please make a video about how to prove a utility function is convex to its origin?? Example:

U=x to the power of delta mutiply by y to the power of beta!!! Sorry i don't know how to write it in the mathematical way!!!

[intromediateecon]

@thienthan07 I'm not sure that one warrants an entire video. I'll give a hint instead of giving away the answer: An indifference curve is convex to the origin when it gets flatter as X increases (graph it if the words seem foreign). Referencing this video's topic, what does that mean about marginal rate of substitution as X increases?

[dxls89]

ur amazing! a really good explanation!!

[quittner]

could you please do a numeric example?? great explanation though

[intromediateecon]

@quittner Lecture 6 gives a numeric example for this. This is the calc-based version of my explanation of marginal rate of substitution. In Lecture 6, I go through the same reasoning with numbers (and without calculus).

[fladdog]

this is very good.

[laughingjal]

wow! eureka...thank you so much for that wonderful explanation!