A woman starts chasing a man when she is really into him. Women generally desire a man who is chivalrous, kind, and possesses impressive talents. Some women also chase men who are mysterious and don't give them the attention they crave.
Typically not in a literal sense, but generally women do like being pursued. What I mean is, most women want a man that is aggressive (in a positive way). These women tend to want attention, to know that they are desired and that a man is willing to work for her. Not all women are like this, but many are.
It's flattering, and it does her heart good to know she's still attractive. The older she is, the more likely she'll crave this ego boost. So if you've noticed older women leading you on, it's because you give her the fun and validation she needs.
If she waits a long time to reply, she might be playing hard to get. Ask her out on a date. If she won't commit to the date and just says to wait and see, she may be stringing you along. Pay attention to how she acts.
If her attention is primarily on anything other than you, and if she doesn't seem excited to be spending time with you, that's the number-one universal sign that you're not her #1 choice. If she: Is constantly checking her phone. Acts like there's somewhere else she needs or wants to be.
The answer is Dopamine. A drug like chemical that pulsates the body in search of pleasure. The dopamine-driven reward loop triggers a rush of euphoric drug-like highs when chasing a crush and the desire to experience them repeatedly.
The best way to make her miss you is to give her the time of her life. Take her to amazing dates, cook her delicious meals or even make her go crazy with your amazing sex skills. Sing to her or take her somewhere special that she didn't expect at all.
The truth about women who play hard to get is that they don't take initiative. In other words, she is waiting to see what you're going to do next. She wants to see if you're truly interested in her without her doing anything to impress you. In a way, she is testing your intentions.