Better Live$, $ati$faction and Happine$$

The Lillenfield text book discusses a common misconception, "Money makes us happy." Kesebir and Diener found this statement to be false due to the lack of long-term effect money has on our happiness. However, they also found that a lack of money can lead to more unhappiness/stress compared to someone with an annual income above $50,000. The benchmark plays a vital role because above the benchmark, people will not feel any happier.
I agree with their statement that money can bring someone joy short-term, but not last. I strongly agree that not having a sufficient amount of money to sustain one's life can greatly affect happiness. Not having money for groceries, bills, entertainment, school etc. makes living challenging and stressful. Having enough money for all one's needs simply crosses those worries off the list, less stress=more smiles.
One study, performed at Princeton University's Woodrow Wilson School, mostly agreed with the Lillenfield statement, but went into greater depth. Their study sets a differing benchmark of $75k a year and introduces two types of happiness related.
The first type of happiness is one's "day-to-day" mood which can be wiped clean over-night, influenced by the weather, or kept for a week. The second type of happiness is one's overall self-satisfaction with life and accomplishments. This study found that the amount of money one has does not affect type 1 happiness (if one's sick in the morning and feeling sad, the amount of money owned will not make one feel better.). However, type 2 happiness is affected by the 75k benchmark. I believe this is due to people's satisfaction with their ability to provide for themselves/their family and a way to grade their success.
The differing benchmark may have to do with the area/type of population they tested compared to Lillenfield's benchmark. The Princeton study is unsure why theirs is set at $75k a year. However, they found sufficient evidence that above or below the mark make a difference.
I completely agree with the second study as well. If I were to say, flunk out of college, get a lower-income job (less than benchmark annual income), and go on with my life. I may still be happy emotionally, but not completely satisfied with how my life turned out. I would have a deep unhappiness that would slowly eat away at me. I wonder if people with lower incomes realize this deeper unhappiness. Could the deeper unhappiness assist with a form of depression?